* Migrate theme manager to infrastructure and added it as input to public API instance
* Working event-delegate for PublicAPIInstance
* Theme aware UWP applications
* Theme aware program plugin
* Update query icon on theme change
* Theme aware calculator plugin
* Fix issue with query running before theme change
* Theme based changes in ImageLoader
* Removed ErrorIcon direct references and added references from ImageLoader
* Nit fixes
* Removed unnecessary TODO in UWP.cs
* Added preference to theme based icons
* Added IDisposable interfaces to unsubscribe events
