Add URL caching and URL preloading

[paurakhsharma]

Add an ability to in-memory cache fetched urls so that subsequent video load can be faster.

You can also manually do this:

VideoApis.getVimeoVideoQualityUrls();
// or
VideoApis.getVimeoPrivateVideoQualityUrls();
// or
VideoApis.getYoutubeVideoQualityUrls();

to pre-load video URLs.

This PR also fixes deprecated APIs