[functional][u] extend VLC test to check correct rendering
|Target version:||QA - future|
Currently the VLC test module tests that we can correctly trigger the play of a video and that playing ends but we do not check that the video can actually be correctly rendered.
Could be beneficial to test the rendering of the video, e.g. either start paused at a certain timestamp or frame or configure VLC to still show the last frame after playing the video.