audio/wavpack: Update to upstream release 5.5.0
Details:
- Use GitHub as main site and www.wavpack.com as fallback
- Switch to CMake
- Enable unit tests
- Backport upstream PR https://github.com/dbry/WavPack/pull/125
PR: 265155
Reviewed by: riggs
MFH: 2022Q3
(cherry picked from commit 555a6d0bc81b3533e1acf0a135e0bf6d879dee82)