App config / default languages

Use the app config to control global settings like default languages.

BccmPlayerInterface.instance.setAppConfig(
    AppConfig(
      appLanguage: appLanguage.languageCode, // 2-letter IETF BCP 47 code
      audioLanguage: audioLanguage, // 2-letter IETF BCP 47 code
      subtitleLanguage: subtitleLanguage, // 2-letter IETF BCP 47 code
      analyticsId: analyticsId, // Can be used by analytics services like NPAW
      sessionId: sessionId, // Can be used by analytics services like NPAW
    ),
)