Matroska / Subtitles - Add support for DVB subtitle type - Codec ID: S_DVBSUB

All VLC versions.

Some DVR programs can handle S_DVBSUB tracks in matroska:

| + A track
|  + Track number: 4 (track ID for mkvmerge & mkvextract: 3)
|  + Track UID: 4
|  + Track type: subtitles
|  + Lacing flag: 0
|  + Codec ID: S_DVBSUB
|  + Language: cze
|  + CodecPrivate, length 4

VLC displays only unknown codec dialog. DVB subtitles are pictures (they are not text based). I can provide sample files on request. ffmpeg/ffplay/Mplayer handles these subtitles correctly.

Duplicate of #14577 (closed).

added Status::duplicate label

closed