New: Add Custom Format fields to Discord On Grab notifications

(cherry picked from commit 3a9182b6a6a322a03666592f8e08d4afde11ee86)

Closes #8790

src/NzbDrone.Core/Notifications/Discord/DiscordSettings.cs

@@ -19,8 +19,8 @@ namespace NzbDrone.Core.Notifications.Discord
         public DiscordSettings()
         {
             // Set Default Fields
-            GrabFields = new List<int> { 0, 1, 2, 3, 5, 6, 7, 8, 9 };
+            GrabFields = new[] { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12 };
-            ImportFields = new List<int> { 0, 1, 2, 3, 4, 6, 7, 8, 9, 10, 11, 12 };
+            ImportFields = new[] { 0, 1, 2, 3, 4, 6, 7, 8, 9, 10, 11, 12 };
             ManualInteractionFields = new[] { 0, 1, 2, 3, 5, 6, 7, 8, 9 };
         }