HTTP 2.0 Support

[saviorand]

The framework should support sending and receiving HTTP 2.0 requests

[mikeball]

Could you just skip HTTP/2, and only build out support for HTTP/1.1 and HTTP/3? Seems like that might be better use of limited time given it's significantly different and more performant and the future default choice and build the code base to handle HTTP/3 going forward. I suspect for some time any mojo web apps will be fronted by nginx/caddy and so HTTP/1.1 and plain HTTP should suffice until it needs to run publicly.

[saviorand]

@mikeball Hmm, good point. I think I'll keep this issue open still, but will open a new one for HTTP/3. We'll likely need /2 support in the future at some point still. Thanks for the suggestion!

[saviorand]

Added an issue for HTTP/3 here #53