multimedia/{,lib}openshot: fix OPTIONS and audio output device selection
Documents that require doxygen have been separated into DOXYGEN option.
It is off by default.
This should fix an issue where no matter what we choose, we could only
output audio to the default sink.
In particular, it is a fix that has become necessary to make JACK work well.
Fixed stage-qa error - link with libpython.
PR: 277648