Clean up editor tools when entering play mode, notably camera preview doesn't stick around in play mode anymore

Author: johncosfm

game/addons/tools/Code/Scene/SceneView/SceneViewportWidget.Game.cs

@@ -40,6 +40,7 @@ public void OnViewModeChanged( SceneViewWidget.ViewMode viewMode )
 	public void SetGameView()
 	{
 		GameMode.SetPlayWidget( Renderer );
+		Tools.ClearScreen();
 		IsGameView = true;
 	}
 
@@ -82,6 +83,7 @@ public void OnEject()
 	public void OnPossessGame()
 	{
 		GameMode.SetPlayWidget( Renderer );
+		Tools.ClearScreen();
 		IsGameView = true;
 	}
 }

game/addons/tools/Code/Scene/Tools/EditorToolManager.cs

@@ -188,6 +188,14 @@ private void CreateToolFor( Type t )
 		}
 	}
 
+	public void ClearScreen()
+	{
+		foreach ( var tool in ComponentTools )
+			tool?.Dispose();
+		ComponentTools.Clear();
+		previousHash = -1;
+	}
+
 	/// <summary>
 	/// Switches to the named tool type next editor frame.
 	/// </summary>