Add support for tvOS
This was tested with prebuilt TVVLCKit only. There is no compatibility with custom VLCKit builds.
When VLCMediaLibraryKit was compiled both for iOS and tvOS, x xcframework including binaries for both OS will be created, otherwise just for the OS the library was compiled for.
The xcframework is no longer created by default. The newly introduced -f flag must be used.
This MR also renames the previous -t option used to skip the compilation of libvlc's extras/tools to -l.