* Changed `GetThemeMedia` to support SortBy/Order options
The `GetThemeMedia, `GetThemeVideos` and `GetThemeSongs` functions can optionally sort the results based based on passing an ItemSortBy type and a SortOrder.
This is intended to be used by jellyfin-web in order to allow users to control the order of theme playback.
See PR: https://github.com/jellyfin/jellyfin-web/pull/5714
* Update MediaBrowser.Controller/Entities/BaseItem.cs
Fix the `GetThemeVideos` two argument overload having both parameters defaulted.
For the two argument overload, both parameters are required.