* [libflac] Bump to 1.4.2.
- The license was incorrectly set to GFDL instead of BSD-3.
See: https://github.com/xiph/flac#components
- Remove patches that were merged upstream.
- Stack protection and fortify source under mingw is checked upstream.
- CMake config file location has changed.
- Use vcpkg_install_copyright to install license.
* [libflac] Add usage file.
* [libflac] Update baseline.
