Microphone implements FixedSource

[yara-blue]

Due to the orphan rule this was hard to do in rodio-experiments. So doing this directly under and experimental flag here.

I plan to gradually move over FixedSource stuff from rodio-experiments over the next month. It will all be under the experimental feature until we're confident we no longer need to release hot-fixes for the current stable.

In my head the timeline is:

1. fix current stable
2. review & merge new Source contract
3. review & merge new Resampler
4. review & merge FixedSource and ConstSource basics from rodio-experiments
5. remove experimental flag for new sources
6. review & merge FixedSource parts in multiple small PR's
7. release next rodio
8. (controversial) deprecate dynamic parts that no longer make sense, backed by performance measurements

Somewhere in between I also hope to add latency & realtime profiling tooling

[roderickvd]

How could I object? 😆

I wouldn't mind a different name for "Microphone" because like "Speaker" they are specific names for things that could be other capture/input respectively playback/output devices. Not particular to this PR though.

[yara-blue]

I wouldn't mind a different name for "Microphone" because like "Speaker" they are specific names for things that could be other capture/input respectively playback/output devices. Not particular to this PR though.

Good point, Speaker is a placeholder for the current Sink. Microphone behaves like a Source sooo .... DeviceCapture mhm? If anyone ever thinks of something a proposal issue is very welcome!