Handling Results throughout the crate

[ryan-summers]

Fixes #113 by handling all the various Result<> types and propogating them upwards to poll(). For now, they are simply logged. In the future, it could be helpful to push these outwards and have poll() return the Result<> type, however I'm hesitant to introduce a breaking API change right now. I'll spawn an issue for this.

This also fixes #58 by propagating the errors described to the new log macros.

[eldruin]

Looks good to me, thank you!
I guess this does not need an entry in the changelog if the changes are all internal.

[mvirkkunen]

Just out of interest, did you make sure that e.g. the state changes in ControlPipe still work correctly even though the functions may return early now? I seem to remember that there were already some problems in there because error handling was "too strict" and in a lot of cases it might have been better to just ignore some of them because implementations can be racey and/or broken.

[ryan-summers]

Just out of interest, did you make sure that e.g. the state changes in ControlPipe still work correctly even though the functions may return early now? I seem to remember that there were already some problems in there because error handling was "too strict" and in a lot of cases it might have been better to just ignore some of them because implementations can be racey and/or broken.

It's hard to say for sure or not because most of the errors would originate in the actual PHY implementation. That being said, I've tested this on both Linux and Windows with an STM32F4 and an H7, and both enumerated properly with both Release and Debug builds.

I think most of the racey and/or broken communication issues were control-pipe related and got fixed up in #142

While there's a possibility that issues could be getting introduced, the new logging features should make them simpler to work through when they occur.

[ryan-summers]

Going to merge this in favor of moving forwards, but will definitely keep an eye out for regressions, thanks for bringing this up @mvirkkunen.