Adding Header.Select fromSafe, toRaw multiple, and Aux

[zarthross]

Some enhancements needed to help enable Rho support.

See: http4s/rho#501 for some usage example.

I could use feedback on these, once I get buy in I'll happily add/fixup the unit tests!

Resolves #4706

[rossabaker]

We should probably target 0.22 with this: that's where the new header model debuts. It shouldn't be hard to merge to main, since it's pure work.

[zarthross]

We should probably target 0.22 with this: that's where the new header model debuts. It shouldn't be hard to merge to main, since it's pure work.

Done.

[rossabaker]

Haven't forgotten this. 0.21 sucked up all my time, but this is absolutely necessary before 0.22 so we don't leave rho hanging. Extra opinions welcome.

[rossabaker]

So this is still in draft. We want to release 0.22.0, but are blocked by a couple issues and circe. I also want to unblock Rho. We could merge this as is and clean it up before the final release, or we could let rho work off snapshots/source dependencies and clean up before the final release. Thoughts?

[zarthross]

I think I can make some time this weekend for the suggestions here, and hopefully any associated testing.

[rossabaker]

That sounds great. I have a stupid busy weekend, so if we can get things greened up, I may do a milestone today. But I will commit to do another release as soon as this is ready, because we don't want to leave Rho hanging.

[zarthross]

Just 2 questions that need answering on the above issues, and I'd be ready to move this out of Draft.

[rossabaker]

I think this is sufficient, and we can do an RC with it when circe-0.14 is ready and make sure Rho has a path forward.

We broke a test

[rossabaker]

Looks like we also broke this:

 ==> X org.http4s.client.middleware.LoggerSuite.RequestLogger should not affect a Post  0.008s org.http4s.ParseFailure: Invalid Content-Type header: Content-Type header doesn't support media ranges

[zarthross]

Looks like we also broke this:

 ==> X org.http4s.client.middleware.LoggerSuite.RequestLogger should not affect a Post  0.008s org.http4s.ParseFailure: Invalid Content-Type header: Content-Type header doesn't support media ranges

I can take a look.