Added Artist search API support.
Added Album search API support.
Added Track search API support.
Added basic UI for searching artists.
Change API methods to be async.
Added download button to artist.
Added Entity Framework and some simple DB entities.
Added UI components for displaying artist statistics.
Added indices to the relevant db columns.
Added Spotify detailed artist/album lookup API methods.
Artists can now be saved on DB.
Added Artist album summaries.
Fixed XML parsing bug on tracks with Various Artists.