Marked as WIP since it depends on !8175 for the test to run reliably (and currently includes its commits).
Tests should be run both with HKCU\Software\Wine\MediaFoundation\DisableGstByteStreamHandler enabled and disabled.
-- v4: mf: Handle thinning in media session. mf: Don't forward thinning to clock. mf/tests: Add tests for thinning. mf/tests: Move some functions. mf/tests: Rename test_seek_source to test_source. mf/tests: Rename test_source to test_stub_source.