[IPlayer] Add struct SPlayerAudioStreamInfo and GetAudioStreamInfo(int iStream, SPlayerAudioStreamInfo &info).
[Players/GUI/LegacyPlayer/JSON] Remove
    GetAudioStreamLanguage(int iStream, CStdString &strLanguage)
    GetChannels()
    GetAudioCodecName()
    GetAudioStreamName(int iStream, CStdString &strStreamName)
from all players and replace them with GetAudioStreamInfo(int iStream, SPlayerAudioStreamInfo &info).
[IPlayer] Add struct SPlayerSubtitleStreamInfo and GetSubtitleStreamInfo(int iStream, SPlayerSubtitleStreamInfo &info).

[Players/GUI/LegacyPlayer/JSON] Remove
     GetSubtitleLanguage(int iStream, CStdString &strStreamLang)
     GetSubtitleName(int iStream, CStdString &strStreamName)
from all players and replace the calls to them with calls to GetSubtitleStreamInfo(int iStream, SPlayerSubtitleStreamInfo &info).
[Players] Remove unused method GetSubtitleExtension(CStdString &strSubtitleExtension).
[IPlayer] Add struct SPlayerVideoStreamInfo and GetAudioStreamInfo(SPlayerVideoStreamInfo &info).

[Players/GUI] Remove
    GetVideoBitrate()
    GetVideoCodecName()
    GetVideoAspectRatio(float& fAR)
    GetVideoRect(CRect& SrcRect, CRect& DestRect)

from all players and replace the calls to them with calls to GetVideoStreamInfo(int iStream, SPlayerAudioStreamInfo &info).
Merge pull request #2269 from ace20022/getXxxStreamInfo

[IPlayer et al.] Replace various Getxxx methods with GetxxxStreamInfo methods