[refactor] Introduce PluginAware utility class

[jhamon]

Problem

As I've been working on bringing in inference features and asyncio stuff, I felt like I was duplicating too much code related to plugins. I decided to pull the setup steps into a new class, PluginAware which pluggable classes may extend.

Solution

• I have made all the currently pluggable classes (Pinecone, PineconeGRPC, Index, Inference) extend PluginAware and deleted duplicated code. In order to be pluggable, a class must have attributes for config, openapi_config, pool_threads and rely on conventional openapi libraries (e.g. generated Api classes and ApiClient) for network calls.

• I have removed the plugin code from Asyncio variant classes (PineconeAsyncio, AsyncioIndex, AsyncioInference) because even though these are built around openapi internals they require async context management that is incompatible with the current plugin approach (which news up a fresh copy of ApiClient for each plugin).

• I removed plugin code from GRPCIndex. As far as I know this was never used and it seems confusing trying to figure out how this fits into the picture with plugins as the plugin stuff is very openapi centric. Also since we seldom build grpc stuff first, I don't think we can expect to need this capability.

Type of Change

• None of the above: Refactor

Test Plan

I did a bit of manual testing and looking at logs to confirm this seems to work after the changes. I tested with the assistant plugin which installed into the Pinecone class without errors.

[austin-denoble]

Nice idea. 👍