api error handler

[vladmandic]

with increased usage via api, there are quite a few issues where user has no idea what is the problem or how to troubleshoot it due to error messages coming from fastapi/starlette/anyio could not be more crtptic

this pr replaces fastapi exception handler with a custom one (both using pretty-printed version or normal python traceback are supported)

note: pretty-print uses rich as formatter which is same as accelerate, so its no a new requirement, i just wanted to be explicit about loading it and have a fallback if its not available

global handler?

if there is interest, i can extend this same exception handler to cover entire webui
(api always needs a separate handler anyhow due to how fastapi works internally)

new api error handling

clear error message and source

API error: GET: http://127.0.0.1:7860/sdapi/v1/progress {'error': 'NameError', 'detail': '', 'body': '', 'errors': "name 'unknown' is not defined"}

╭─────────────────────────────── Traceback (most recent call last) ────────────────────────────────╮
│ /home/vlado/dev/automatic/modules/api/api.py:136 in exception_handling                           │
│                                                                                                  │
│   135 │   │   try:                                                                               │
│ ❱ 136 │   │   │   return await call_next(request)                                                │
│   137 │   │   except Exception as e:                                                             │
│                                                                                                  │
│ ╭─────────────────────────────────────────── locals ───────────────────────────────────────────╮ │
│ │        call_next = <function BaseHTTPMiddleware.__call__.<locals>.call_next at               │ │
│ │                    0x7f94a39ac280>                                                           │ │
│ │                e = NameError("name 'uknown' is not defined")                                 │ │
│ │ handle_exception = <function api_middleware.<locals>.handle_exception at 0x7f94a3919480>     │ │
│ │          request = <starlette.requests.Request object at 0x7f94a39a2650>                     │ │
│ ╰──────────────────────────────────────────────────────────────────────────────────────────────╯ │
│                                                                                                  │
│ /home/vlado/.local/lib/python3.10/site-packages/starlette/middleware/base.py:84 in call_next     │
│                                                                                                  │
│                                     ... 19 frames hidden ...                                     │
│                                                                                                  │
│ /home/vlado/.local/lib/python3.10/site-packages/anyio/_backends/_asyncio.py:867 in run           │
│                                                                                                  │
│ /home/vlado/dev/automatic/modules/api/api.py:403 in progressapi                                  │
│                                                                                                  │
│   402 │   │   if shared.state.job_count == 0:                                                    │
│ ❱ 403 │   │   │   return ProgressResponse(uknown, progress=0, eta_relative=0, state=shared.sta   │
│   404                                                                                            │
│                                                                                                  │
│ ╭────────────────────── locals ──────────────────────╮                                           │
│ │  req = ProgressRequest(skip_current_image=False)   │                                           │
│ │ self = <api.py.ApiHijack object at 0x7f94a3ab46a0> │                                           │
│ ╰────────────────────────────────────────────────────╯                                           │
╰──────────────────────────────────────────────────────────────────────────────────────────────────╯
NameError: name 'uknown' is not defined

old api error handling

unreadable and whats worse, it doesn't even show where error comes from

ERROR:    Exception in ASGI application
Traceback (most recent call last):
  File "/home/vlado/.local/lib/python3.10/site-packages/anyio/streams/memory.py", line 94, in receive
    return self.receive_nowait()
  File "/home/vlado/.local/lib/python3.10/site-packages/anyio/streams/memory.py", line 89, in receive_nowait
    raise WouldBlock
anyio.WouldBlock

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/home/vlado/.local/lib/python3.10/site-packages/starlette/middleware/base.py", line 78, in call_next
    message = await recv_stream.receive()
  File "/home/vlado/.local/lib/python3.10/site-packages/anyio/streams/memory.py", line 114, in receive
    raise EndOfStream
anyio.EndOfStream

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/home/vlado/.local/lib/python3.10/site-packages/uvicorn/protocols/http/h11_impl.py", line 407, in run_asgi
    result = await app(  # type: ignore[func-returns-value]
  File "/home/vlado/.local/lib/python3.10/site-packages/uvicorn/middleware/proxy_headers.py", line 78, in __call__
    return await self.app(scope, receive, send)
  File "/home/vlado/.local/lib/python3.10/site-packages/fastapi/applications.py", line 273, in __call__
    await super().__call__(scope, receive, send)
  File "/home/vlado/.local/lib/python3.10/site-packages/starlette/applications.py", line 120, in __call__
    await self.middleware_stack(scope, receive, send)
  File "/home/vlado/.local/lib/python3.10/site-packages/starlette/middleware/errors.py", line 184, in __call__
    raise exc
  File "/home/vlado/.local/lib/python3.10/site-packages/starlette/middleware/errors.py", line 162, in __call__
    await self.app(scope, receive, _send)
  File "/home/vlado/.local/lib/python3.10/site-packages/starlette/middleware/base.py", line 108, in __call__
    response = await self.dispatch_func(request, call_next)
  File "/home/vlado/dev/automatic/modules/api/api.py", line 96, in log_and_time
    res: Response = await call_next(req)
  File "/home/vlado/.local/lib/python3.10/site-packages/starlette/middleware/base.py", line 84, in call_next
    raise app_exc
  File "/home/vlado/.local/lib/python3.10/site-packages/starlette/middleware/base.py", line 70, in coro
    await self.app(scope, receive_or_disconnect, send_no_error)
  File "/home/vlado/.local/lib/python3.10/site-packages/starlette/middleware/cors.py", line 84, in __call__
    await self.app(scope, receive, send)
  File "/home/vlado/.local/lib/python3.10/site-packages/starlette/middleware/gzip.py", line 24, in __call__
    await responder(scope, receive, send)
  File "/home/vlado/.local/lib/python3.10/site-packages/starlette/middleware/gzip.py", line 44, in __call__
    await self.app(scope, receive, self.send_with_gzip)
  File "/home/vlado/.local/lib/python3.10/site-packages/starlette/middleware/exceptions.py", line 79, in __call__
    raise exc
  File "/home/vlado/.local/lib/python3.10/site-packages/starlette/middleware/exceptions.py", line 68, in __call__
    await self.app(scope, receive, sender)
  File "/home/vlado/.local/lib/python3.10/site-packages/fastapi/middleware/asyncexitstack.py", line 21, in __call__
    raise e
  File "/home/vlado/.local/lib/python3.10/site-packages/fastapi/middleware/asyncexitstack.py", line 18, in __call__
    await self.app(scope, receive, send)
  File "/home/vlado/.local/lib/python3.10/site-packages/starlette/routing.py", line 716, in __call__
    await route.handle(scope, receive, send)
  File "/home/vlado/.local/lib/python3.10/site-packages/starlette/routing.py", line 276, in handle
    await self.app(scope, receive, send)
  File "/home/vlado/.local/lib/python3.10/site-packages/starlette/routing.py", line 66, in app
    response = await func(request)
  File "/home/vlado/.local/lib/python3.10/site-packages/fastapi/routing.py", line 237, in app
    raw_response = await run_endpoint_function(
  File "/home/vlado/.local/lib/python3.10/site-packages/fastapi/routing.py", line 165, in run_endpoint_function
    return await run_in_threadpool(dependant.call, **values)
  File "/home/vlado/.local/lib/python3.10/site-packages/starlette/concurrency.py", line 41, in run_in_threadpool
    return await anyio.to_thread.run_sync(func, *args)
  File "/home/vlado/.local/lib/python3.10/site-packages/anyio/to_thread.py", line 31, in run_sync
    return await get_asynclib().run_sync_in_worker_thread(
  File "/home/vlado/.local/lib/python3.10/site-packages/anyio/_backends/_asyncio.py", line 937, in run_sync_in_worker_thread
    return await future
  File "/home/vlado/.local/lib/python3.10/site-packages/anyio/_backends/_asyncio.py", line 867, in run
    result = context.run(func, *args)
  File "/home/vlado/dev/automatic/modules/api/api.py", line 368, in progressapi
    return ProgressResponse(unknown, progress=0, eta_relative=0, state=shared.state.dict(), textinfo=shared.state.textinfo)
NameError: name 'unknown' is not defined