chore(tests): prepare testing setup for http2 and https

[cyco130]

This PR adds alternative fetch implementations to be used for testing HTTPS and HTTP/2 adapters. It also adds a few lines to make the standard Node adapter work with node:http2 correctly (except for the types).

This should allow testing #185 as well. I've already added an HTTP/2 test (using the standard Node adapter). The types don't match but all tests are passing. It might still take some work to make sure everything works as expected though.

Also added node:https and "uwebsockets.js with SSL" tests.

[aleclarson]

Super cool!

[cyco130]

Looks like Windows can't cleanly close the HTTP/2 connection and Node 18 seems picky about uwebSocket's SSL implementation too. Let's try to address those one by one 😅

[cyco130]

I disabled "uwebSockets.js with SSL" tests on Node 18. We only support Node 18 for StackBlitz and StackBlitz will switch to v20 soon. And it can't run uwebSockets.js anyway. No need to spend more time on it.

I opened a separate issue for the Windows failure. I don't have a Windows machine and it's almost impossible for me to investigate. Also, I have a suspicion that it is related to my fetch implementation rather than the adapter. No need to block this as we're not breaking anything that wasn't already broken.