Improve streaming interface to provide response info

[iMacTia]

Description

• Add bake-test-external and test faraday-net_http as part of the CI
• Introduce the new streaming API with stream_response helper

Fixes #1426

Todos

List any remaining work that needs to be done, i.e:

• [x] Tests
• [x] Documentation

Additional Notes

• As part of this PR, we're now running faraday-net_http tests as part of CI thanks to bake-test-external 🙌
• However, it seems like bake-test-external is incompatible with Ruby 2.6, so we only run them for Ruby 2.7+
• Rubocop-packaging is currently incompatible with the latest Rubocop release. The fix is on the main branch already, but they haven't released a new version yet, so I've temporarily updated the Gemfile to point to that
• truffleruby-head and ruby-head are back in the CI matrix, but they've been marked as experimental

[iMacTia]

I'd forget about documentation all the time without it 😂