Refactor and more appropriately organize logic

- move play logic to simulation module
- update play hotkey to call play game/scene delegate function
- link hotkey tooltip text to inputOptions

Source/Editor/Editor.cs

@@ -1579,7 +1579,7 @@ namespace FlaxEditor
         private static void RequestStartPlayOnEditMode()
         {
             if (Instance.StateMachine.IsEditMode)
-                Instance.Simulation.RequestStartPlay();
+                Instance.Simulation.RequestStartPlayScenes();
             if (Instance.StateMachine.IsPlayMode)
                 Instance.StateMachine.StateChanged -= RequestStartPlayOnEditMode;
         }