Fix: no emit signal after updating the attribute.

Emit hardware_object_value_changed is called after emitting valueChanged within
update_value method. If _nominal_value was changed by assiging new value to it,
the signals would not be emited in the following steps because _nominal_value
would be already equal to the value when checking.

Author: dominikatrojanowska

mxcubecore/HardwareObjects/mockup/ExporterNStateMockup.py

@@ -107,7 +107,7 @@ def _set_value(self, value):
             else:
                 value = value.value
 
-        self._nominal_value = self.value_to_enum(value)
+        self.update_value(self.value_to_enum(value))
         self.update_state(self.STATES.READY)
 
     def get_value(self):