Update dependencies in positron-proxy extension

[petetronic]

Required updates to at least the following versions:

• http-proxy-middleware@2.0.7 (or later)
• braces@3.0.3 (potentially via http-proxy-middleware@3.0.1 or later)
• micromatch@4.0.8 (potentially via http-proxy-middleware@3.0.1 or later)
• body-parser@1.20.3 (potentially via express@4.20.0 or later)
• express@4.20.0

[timtmok]

Updating to import { legacyCreateProxyMiddleware as createProxyMiddleware, responseInterceptor } from 'http-proxy-middleware'; allows using http-proxy-middleware@3.0.3 without any code changes.

The change we need to adopt is how the proxy options are passed when creating it. It's purely a format change. I've tested it with the new option format and it only seems to work when using the legacy adapter. Otherwise, the proxy doesn't seem to process the requests properly. They come in and are forwarded but it's missing something for the content to load.

So I'm going forward with testing the changes while using the legacy adapter. We have time to figure out what's wrong with the options until the legacy adapter is removed in the future.