Fixed: Speed up UI during refresh

Don't update state if we know items are equal to avoid reselections.
Don't pass LastInfoUpdate to frontend to prevent useless updates (the
field isn't used)

src/Lidarr.Api.V1/Artist/ArtistResource.cs

@@ -20,8 +20,6 @@ namespace Lidarr.Api.V1.Artist
 
         public bool Ended => Status == ArtistStatusType.Ended;
 
-        public DateTime? LastInfoSync { get; set; }
-
         public string ArtistName { get; set; }
         public string ForeignArtistId { get; set; }
         public string MBId { get; set; }
@@ -96,8 +94,6 @@ namespace Lidarr.Api.V1.Artist
                 AlbumFolder = model.AlbumFolder,
                 Monitored = model.Monitored,
 
-                LastInfoSync = model.LastInfoSync,
-
                 CleanName = model.CleanName,
                 ForeignArtistId = model.Metadata.Value.ForeignArtistId,
 
@@ -146,7 +142,6 @@ namespace Lidarr.Api.V1.Artist
                 AlbumFolder = resource.AlbumFolder,
                 Monitored = resource.Monitored,
 
-                LastInfoSync = resource.LastInfoSync,
                 CleanName = resource.CleanName,
                 RootFolderPath = resource.RootFolderPath,