I think this makes the next() function easier to understand. We can
write this more efficiently by reusing a Vec on the struct rather than
allocating each time and a mem::swap to avoid shifting elements in a Vec.
For example, if a stereo source starts playing on an odd-numbered call
to DynamicMixer::next() then the output stream will play its first
sample in the right channel, its second in the left, etc. This is wrong.
The first sample should be played in the left channel.
* Remove unnecessary 'static bound and cleanup
The decoder had an unnecessary 'static bound. Additionally I noticed
that there's a lot of (clippy) warnings, so I cleaned up the code a bit
as well. There's a few warnings left, but a few of those require
breaking changes.
* Address Review Comments
The update required adapting to the breaking changes introduced by the new version, as reported in the `cpal`'s
[changelog](a2fe9386af/CHANGELOG.md), namely:
- Rename `ChannelsCount` to `ChannelCount`.
- Rename `SamplesRate` to `SampleRate`.
- Rename the `min_samples_rate` field of `SupportedFormat` to `min_sample_rate`
- Rename the `with_max_samples_rate()` method of`SupportedFormat` to `with_max_sample_rate()`
- Rename the `samples_rate` field of `Format` to `sample_rate`
- Changed the type of the `channels` field of the `SupportedFormat` struct from `Vec<ChannelPosition>` to `ChannelCount` (an alias to `u16`)
