Add more missing sprites, fix item sprites

Pkmds.Web/Components/EditForms/Tabs/MainTab.razor

@@ -138,7 +138,7 @@ EntityContext.MaxInvalid &&
                 {
                     var pkm = Pokemon.Clone();
                     pkm.HeldItem = item.Value;
-                    <MudImage Src="@SpriteHelper.GetBigItemSpriteFilename(pkm.SpriteItem)"
+                    <MudImage Src="@SpriteHelper.GetArtworkItemSpriteFilename(pkm.SpriteItem)"
                               ObjectFit="@ObjectFit.Contain"
                               ObjectPosition="@ObjectPosition.Center"
                               Width="22"

Pkmds.Web/SpriteHelper.cs

@@ -28,6 +28,9 @@ public static string GetBallSpriteFilename(int ball) =>
     public static string GetBigItemSpriteFilename(int item) =>
         $"sprites/bi/bitem_{item}.png";
 
+    public static string GetArtworkItemSpriteFilename(int item) =>
+        $"sprites/ai/aitem_{item}.png";
+
     public static string GetTypeGemSpriteFileName(byte type) =>
         $"sprites/t/g/gem_{type:00}.png";