set fit toolbar a name; fixes #281

src/gui_qt/fit/fit_toolbar.py

@@ -10,7 +10,7 @@ class FitToolbar(QtWidgets.QToolBar):
             limit_menu: QtWidgets.QMenu,
             parent=None,
     ):
-        super().__init__(parent=parent)
+        super().__init__('Fit', parent=parent)
 
         self.fit_action = fitaction
         self.region = RegionItem()