Extract embassy support into esp-hal-embassy package

[jessebraham]

Let's try this again 😁

I've opened this PR as a draft for the time being as it still needs a README.md file for the new package, and I still need to finish documenting the new package as well. However, in the meantime, we can at least review the code changes. I will get this wrapped up on Monday.

I've done some very minimal testing and things seem to be in order, however more thorough testing is still required.

Closes #1035

[jessebraham]

I'm not sure why this was necessary, probably I'm missing something?

[jessebraham]

Still need to finish documentation and review further, but rebased my branch and updated the defmt support. I don't know if I handled this correctly or not (just dumped in fmt.rs from esp-hal) so let me know if I need to change this.

[jessebraham]

The README.md could definitely use some expansion, however I'm not really sure what should be included here and what belongs in documentation.

[SergioGasquez]

Shall we add some links to the embassy book or to website? They are just 1 click further from the repo, but it might be useful.

[bjoernQ]

Seems I have problem using the systimer-time-driver and running e.g. the embassy-hello-world code. Using timg0-driver works

[jessebraham]

Looking into it

[jessebraham]

Seems to be broken on main too, so much have happened during the timer abstraction work at some point.

[jessebraham]

Okay I cannot for the life of me figure out why the "correct" fix for this isn't working. I've debugged my implementation, everything appears to be correct, but it's just plain not working.

So, I give up on that. I've included a hacky "fix", which is pretty objectively bad, but also it's not like we're not doing this all over the code base already. Ideally I'd like to fix this, however I also would like to get this merged and released so I can stop thinking about timers for awhile.

If anybody else wants to take a swing at a better fix please feel free, or if you have any suggestions I can try them out.

[bjoernQ]

LGTM - Thanks!

[MabezDev]

Thanks! Nice to see this split out, and a bunch of features removed from esp-hal.

The last piece of this puzzle will be docs I think, but we already have to figure that out for esp-wifi, so we can do that later.