Add support for HTTP/2, HTTP/3, System CA, OCSP Revocation

[Ousret]

Hello HTTPie users,

I am working on native support for HTTP/2 and HTTP/3 and I reached a point where I need testers.
So I am opening that issue to invite anyone willing to explore and report anomalies directly here.

Option A

Run with a plugin, but it is a minimalist implementation.

pip install httpie-next -U

Option B

Use my HTTPie branch for a more "feature"-complete implementation.

pip install git+https://github.com/Ousret/HTTPie.git@feature-tryout-niquests -U

Verify

Run this, to verify it's working properly.

# run twice!
https GET www.cloudflare.com/img/nav/globe-lang-select-dark.svg

[jkbrzt]

@Ousret great stuff, will play with it a report back

[Ousret]

Now directly available through PyPI.

pip install httpie-next -U

[Ousret]

Update: Since last time, a lot has happened.
See #1531 if you want to test this in a more mature form.