added deselecting nodes when left clicking in blank area in the scene and prefab tree views

Source/Editor/Windows/Assets/PrefabWindow.cs

@@ -260,6 +260,12 @@ namespace FlaxEditor.Windows.Assets
                 ShowContextMenu(Parent, ref locationCM);
                 return true;
             }
+
+            if (button == MouseButton.Left && _treePanel.ContainsPoint(ref location))
+            {
+                _tree.Deselect();
+                return true;
+            }
             return false;
         }
 

Source/Editor/Windows/SceneTreeWindow.cs

@@ -442,6 +442,15 @@ namespace FlaxEditor.Windows
                 return true;
             }
 
+            if (buttons == MouseButton.Left)
+            {
+                if (Editor.StateMachine.CurrentState.CanEditScene)
+                {
+                    Editor.SceneEditing.Deselect();
+                }
+                return true;
+            }
+
             return false;
         }