[GUI/Player] Generate a proper subtitle lang-name string for presentation in the osd.
The format of the displayed subtitle string is same as in the settings dialog.
Merge pull request #2782 from ace20022/subs_kai_toast

[GUI/Player] Proper subtitle lang-name string for kai toast
dvdplayer: don't call into audio device from non audio thread

CoreAE has a bug where AddPackets is a blocking operation. This causes
DVDAudio to blocked during this time. Since this is called from rendering
thread, we end up blocking GUI/video rendering.
[Fix/Gui] Change the string format operation for language - name.
This prevents a possible crash while formatting the lang-name string for presentation in the audio dialog.
Merge pull request #2790 from ace20022/lang_string

[Fix/Gui] Change the string format operation for language - name.
[platinum] - fix shadowed local var