move a user more UserAnswer features to base class

rapids/models.py

@@ -771,6 +771,7 @@ class Exam(ExamBase):
 @reversion.register
 class UserAnswer(UserAnswerBase):
     """User answers by candidate"""
+    app_name = "rapids"
 
     question = models.ForeignKey(
         Rapid, related_name="cid_user_answers", on_delete=models.CASCADE
@@ -816,9 +817,7 @@ class UserAnswer(UserAnswerBase):
 
     def __str__(self):
 
-        name = self.cid
-        if self.user is not None:
-            name = self.user.username
+        name = self.get_candidate_name()
 
         try:
             exam = self.exam
@@ -859,9 +858,6 @@ class UserAnswer(UserAnswerBase):
         else:
             return self.answer
 
-    def get_absolute_url(self):
-        return reverse("rapids:user_answer_view", kwargs={"pk": self.pk})
-
     def get_answer_callstate(self):
         if not self.callstate:
             return ""