[widgets][spinbox] Use numpy for string generation from value

beat/editor/widgets/spinboxes.py

@@ -88,7 +88,7 @@ class AbstractNumpySpinBox(QAbstractSpinBox):
 
         :param value numpy_type: value to change to text
         """
-        return "{}".format(value)
+        return self.numpy_type(value).astype("str")
 
     def valueFromText(self, text, pos):
         """Returns the value contained in the text