* Introduce isToolActive function
* Ride window: use isToolActive instead of gCurrentToolWidget
* Footpath window: use isToolActive instead of gCurrentToolWidget
* Staff window: use isToolActive instead of gCurrentToolWidget
* MazeConstruction window: use isToolActive instead of gCurrentToolWidget
* Guest window: use isToolActive instead of gCurrentToolWidget
* Map window: use isToolActive instead of gCurrentToolWidget
* LandRights window: use isToolActive instead of gCurrentToolWidget
* Replace SceneryToolIsActive legacy function with calls to isToolActive
* ClearScenery window: use isToolActive instead of gCurrentToolWidget
* Scenery window: use isToolActive instead of gCurrentToolWidget
* Water window: use isToolActive instead of gCurrentToolWidget
* Land window: use isToolActive instead of gCurrentToolWidget
* Widget: replace WidgetIsActiveTool with isToolActive
* RideConstruction window: use isToolActive instead of gCurrentToolWidget
* Ride: use isToolActive instead of gCurrentToolWidget
* TrackDesignPlace window: use isToolActive instead of gCurrentToolWidget
* StaffList window: use isToolActive instead of gCurrentToolWidget
* ViewClipping window: use isToolActive instead of gCurrentToolWidget
* PatrolArea window: use isToolActive instead of gCurrentToolWidget
* TileInspector window: use isToolActive instead of gCurrentToolWidget
* Park window: use isToolActive instead of gCurrentToolWidget
