feat: add grading method support for problems with multiple attempts (#33911)

A new field in the Problem settings for choosing a Grading Method. Currently, the only Grading Method is the Last Score. From now on, when turning the feature flag on, the new grading methods available for configuration in Studio are:
- Last Score (Default): The last score made is taken for grading.
- First Score: The first score made is taken for grading.
- Highest Score: The highest score made is taken for grading.
- Average Score: The average of all scores made is taken for grading.

lms/templates/problem.html

@@ -1,7 +1,7 @@
 <%page expression_filter="h"/>
 <%!
 from django.utils.translation import ngettext, gettext as _
-from openedx.core.djangolib.markup import HTML
+from openedx.core.djangolib.markup import HTML, Text
 %>
 
 <%namespace name='static' file='static_content.html'/>
@@ -90,6 +90,9 @@ from openedx.core.djangolib.markup import HTML
         % if attempts_allowed and (not submit_disabled_cta or attempts_used == 0):
           ${ngettext("You have used {num_used} of {num_total} attempt", "You have used {num_used} of {num_total} attempts", attempts_allowed).format(num_used=attempts_used, num_total=attempts_allowed)}
         % endif
+        % if grading_method:
+          <div>${Text(_("Grading method: {grading_method}")).format(grading_method=grading_method)}</div>
+        % endif
         <span class="sr">${_("Some problems have options such as save, reset, hints, or show answer. These options follow the Submit button.")}</span>
       </div>
     </div>