add actors to movies and shows (#172)

* add actor metadata

* show actors in ui

* get full movie/show metadata from plex

* store actor thumbnail url

* rework movie detail page

* metadata fixes

* rework show detail page

* rework artist page

* code cleanup

ErsatzTV/Shared/MediaCard.razor

@@ -119,6 +119,9 @@
     [Parameter]
     public Color SelectColor { get; set; } = Color.Tertiary;
 
+    [Parameter]
+    public bool IsRemoteArtwork { get; set; }
+
     private string GetPlaceholder(string sortTitle)
     {
         if (Placeholder != null)
@@ -130,9 +133,17 @@
         return char.IsDigit(first) || !char.IsLetter(first) ? "#" : first.ToString();
     }
 
-    private string ArtworkForItem() => string.IsNullOrWhiteSpace(Data.Poster)
-        ? "position: relative"
-        : $"position: relative; background-image: url(/artwork/{PathForArtwork()}/{Data.Poster}); background-size: cover; background-position: center";
+    private string ArtworkForItem()
+    {
+        if (IsRemoteArtwork)
+        {
+            return $"position: relative; background-image: url({Data.Poster}); background-size: cover; background-position: center";
+        }
+
+        return string.IsNullOrWhiteSpace(Data.Poster)
+            ? "position: relative"
+            : $"position: relative; background-image: url(/artwork/{PathForArtwork()}/{Data.Poster}); background-size: cover; background-position: center";
+    }
 
     private string PathForArtwork() => ArtworkKind switch
     {