Output the response body when request returns a 400

[JelleZijlstra]

• Python version: 3.9
• Operating System: Ubuntu
• aiohttp version: 3.7.4

I made a request to an SSE endpoint and I hit a 400, but the error just looks like ConnectionError: fetch https://example.com/ failed: 400. To figure out what caused the 400, I had to patch aiohttp-sse-client to include the response body in the error.

It would be useful if the library provided a way to access the response body directly for cases like this. Perhaps the exceptions it throws could include the aiohttp ClientResponse object as an attribute, so callers can call e.response.read() if desired.

[JelleZijlstra]

I created a fork in https://github.com/JelleZijlstra/aiohttp-sse-client2 to fix this issue since development on this repo seems to have stalled. I'll be happy to retire my fork if this repo comes back to life.

If other aiohttp-sse-client users have fixes they'd like to see, feel free to submit them to my fork.