lib: undeprecate libvlc_playlist_play()

On top of !4851 (merged), review only the 3 last commits here.

libvlc_playlist_play is used in the following code:

bin/darwinvlc.m
bin/winvlc.c
bin/vlc.c
test/src/misc/image_cvpx.c
test/src/input/decoder/input_decoder.c
test/src/misc/image.c
test/src/video_output/video_output.c
test/iosvlc.m
test/modules/stream_out/transcode.c
test/modules/misc/medialibrary.c
test/modules/lua/extension.c

And we have no plan for any alternatives.