Support for MKV commentary flag

[roaku 842]

Since the SDH+Commentary flag feature request was closed after the addition of SDH and because I can't find another existing Commentary flag request, here's a request to add Emby support for MKV's commentary flag.

[Luke 42078]

HI, yes ,makes sense. Thanks.

[rbjtech 5284]

Yes this would be nice.  +1

I currently have added this myself on the MediaInfo Plugin where it uses this flag or scans the existing track title for the word 'commentary' and then adds it to the end of the new track title, plus tags it as well.     This allows limited searching (via tag) and gives the user the detail in the drop down it's a commentary track - but useful info, such as who is doing the commentary is lost unfortunately.

But would love to see this as a proper db item