Add better support for subtitles in SDK
Given the ID of a media asset, there is no way to determine whether there is a subtitles file for that asset, except to search within the asset for a suitable file by the file extension. (i.e. get an asset that ends with VTT) And then, if you find one, there is no way to know what language it contains. There should be a way to do this through the SDK, storing the name of a subtitles file and its language attribute so that playback requires only the streaming URL to the asset, and the manifest would be properly updated to include the subtitles file, or we could get the subtitles URL from the .Net SDK or REST API.