Add Simple Media File Format support, an in-house, quick-made alternative audio/video file container that supports opus, AV1, H264, H265, VP8 codecs.
It is not interoperable, but may be used instead of matroska when video codecs other than VP8 or H264 must be supported for recording calls and playing them.

Added player and recorder mediastreamer2 test program. Improve MSMediaRecorder and MSMediaPlayer.