Able to remove empty translations

src/model/translation.py

@@ -38,3 +38,12 @@ class Translation(Editable):
         self.explanation = explanation.textContent if explanation else ""
         self.tags = import_label_list("labelList label", translation_xml)
     
+    def is_empty(self):
+        result = True
+        result = result and self.translation == ""
+        # next two are not checked as the also can not be deleted via gui
+        # result = result and self.source == ""
+        # result = result and self.targetLang == ""
+        result = result and self.explanation == ""
+        result = result and len(self.tags) == 0
+        return result