Gui: fix warnings reported by GH Actions:

* Fix trailing spaces
* Replace tabs
* Mark constructors with one argument explicit
* Fix typos
* Include FCGlobal.h to fix parsing errors

src/Gui/CommandView.cpp

@@ -2599,7 +2599,7 @@ void StdViewBoxZoom::activated(int iMsg)
         View3DInventorViewer* viewer = view->getViewer();
         if (!viewer->isSelecting()) {
             SelectionCallbackHandler::Create(viewer, View3DInventorViewer::BoxZoom, QCursor(QPixmap(cursor_box_zoom), 7, 7));
-		}
+        }
     }
 }