Support 5.1 and other channel layouts

[GWBasic]

This website explains the channel layout of 5.1 wav files: https://www.jensign.com/bdp95/7dot1voiced/index.html

It then links to a more detailed document from Microsoft about varying channel layout. (IE, how to disambiguate from 3.1 versus quad: https://learn.microsoft.com/en-us/previous-versions/windows/hardware/design/dn653308(v=vs.85)?redirectedfrom=MSDN

One important change needed in wave_stream is supporting channelMask

[GWBasic]

Converted the headers to handle WAVEFORMATEX. Currently refactoring so that reading/writing works with a SamplesByChannel struct that specifies the sample for each channel by speaker location instead of numerical index.

Writing is almost completed (just need to update tests.) Need to update reading.

[GWBasic]

Started updating the example: GWBasic/wave_stream_example#1

Changes needed:

• Need to test a proper 5.1 wav in Kodi
• Need to update sample code in lib.rs
• Need to publish a new revision to crates.io
• Need to update the sample