Add support for switching the zlib implementation

[bdraco]

Is your feature request related to a problem?

I'm currently maintaining https://github.com/bdraco/aiohttp-fast-zlib which allows swapping out the standard lib zlib for isal or zlib-ng since its a ~5x performance improvement

Describe the solution you'd like

Native support

Describe alternatives you've considered

n/a

Related component

Server

Additional context

No response

Code of Conduct

• I agree to follow the aio-libs Code of Conduct

[Dreamsorcerer]

I'd note that we do have downstreams that use zlib-ng as the default zlib library. We had a complaint that the zlib tests were failing in their environment, and it was because they were using zlib-ng and thus getting different binary representations.

Not against allowing different Python libraries though.

[bdraco]

I recall seeing that. Do you happen to remember the issue where it was reported. It would be good to make sure the tests are adjusted to pass for isal, zlib, and zlib-ng

[bdraco]

found #7255

[Dreamsorcerer]

Yes, as I mentioned at that time, we should keep the binary tests as internal and add new tests which verify the decompressed results.

The binary tests are useful to tell if we've messed up the compression in our code (we had a PR which clearly broke the compression efficiency by restarting the compression on each line or something).