Async serial uart read

[alexiionescu]

serial uart read for embassy async

Also fix an issue with async write on large buffers, was panicking with Err Would Block. Discovered when testing reading and echoing back a large reader buffer.
Tested on ESP32C3 (WROOM) only using a separate project. Examples do not work on riscv at the moment (see issue #604)

I will use this on a separate larger project that requires a serial bridge between PC and a network of ESP32C3 (WROOM) communicating via ESP-NOW. I might revisit it and fix some issues if I find any.

NOTE: embassy_hal_async does not have a Read trait for serial, only Write traits, so I could not follow the same implementation pattern as in the write case. The new function is called read, not sure if it is Ok, there was not a read function for nb implementation. If you think is to generic, I can change it to read_async

Must

• The code compiles without errors or warnings.
• All examples work.
• cargo fmt was run.
• Your changes were added to the CHANGELOG.md in the proper section.
• You updated existing examples or added examples (if applicable).
• Added examples are checked in CI

Nice to have

• You add a description of your work to this PR.
• You added proper docs for your newly added features and code.

[MabezDev]

Thanks for looking into this! This is a good first iteration but I have a few comments I think we should address :).

[MabezDev]

Thanks, nearly there, just a few more little bits to address :)

[MabezDev]

Can't we just use read() here? We could do while let Ok(byte) = self.read() instead of duplicating some code.

[MabezDev]

Let's document that read might not fill buf completely.

[alexiionescu]

I will also insert an error case Error::ReadBufferFull when provided buffer size is not enough.

[MabezDev]

Did you mean to close this @alexiionescu?

[alexiionescu]

No, I messed up my pull request branch by merging the latest from upstream in order to run the examples.
Bad Idea !!!
Now I have rebased to the initial commit before merge and staged all my modifications again. After I am done I need to force push it again I guess and discard all other changes.I read this might re-open the PR?
Any better idea what to do in this case?

Also someone has rewrite the examples to use the same type on all examples and I have already merged that changed

    interrupt::enable(Interrupt::UART0, interrupt::Priority::Priority1).unwrap();

I can keep the merging, although I guess the CI will fail.

[alexiionescu]

I have pushed the commit before the force-push closed. I don't think I can re-open it myself.

[alexiionescu]

I have also pushed my latest changes based on your review. Please let me know If I need to make a new PR or you can re-open this.