Fix BaseItemKind conversion for PlaylistsFolder #5228
Return the correct ClientTypeName to allow Enum Parse
The reason to create a test project depending on the executing assembly is to be sure to catch all instances of the classes:
So instead of adding a new project (Emby.Server.Implementation.Tests) and duplicate the test, I've added a single project and single test.
Aligned code base to review comments: Jellyfin.Server.Implementation.Tests is the correct place