Add Resume/Exit buttons to pause menu, handle logic for returning to main menu and starting a new game

Zennysoft.Game.Ma/src/ui/gallery/GalleryMenu.cs

@@ -56,8 +56,17 @@ public partial class GalleryMenu : Control
 
   public void OnReady()
   {
-	GalleryData = new GalleryData() { PlaceholderImage1 = true };
-	BackButton.Pressed += BackButton_Pressed;
+    GalleryData = new GalleryData() { PlaceholderImage1 = true };
+    BackButton.Pressed += BackButton_Pressed;
+  }
+
+  public override void _Input(InputEvent @event)
+  {
+    if (!Visible)
+      return;
+
+    if (@event.IsActionPressed(GameInputs.Interact))
+      BackButton.GrabFocus();
   }
 
   private void BackButton_Pressed() => EmitSignal(SignalName.GalleryExited);