players: move more things into info structures for audio/video
dvdplayer: don't constantly hammer demuxer to get stream count

Note this could cause regressions in files where streams show
up during playback, but i think the demuxer signals such
situations now.
videodb: make sure to return the same playcount (0 or 1) for tvshows (fixes #14703)
Merge pull request #3691 from Montellese/tvshows_playcount

videodb: make sure to return the same playcount (0 or 1) for tvshows (fixes #14703)
don't constantly hammer demuxer to get stream count

Note this could cause regressions in files where streams show
up during playback, but i think the demuxer signals such
situations now.
Merge pull request #3663 from elupus/dvdlocks

Some cleanups in gui/player callbacks
CharsetDetection::GetBomEncoding: fix: remove unused leftover parameter
StringUtils::TrimLeft: fix: if string contains only trim chars then string must be erased instead of left untouched