You can now package as many platforms as you want

This removes the forks for iOS and tvOS to achieve a universal API

This moves both sources and headers to new designated places and groups

Previous implementation forced user to get time and position from the main thread and configured the time update loop asynchronously.
These changes are configuring the time update observing loop synchronously and are allowing to get time and position with proper concurrent access.

Related to vlc@12fa8556.

Related to vlc@12fa8556.