feat: added recent sort in learners area

src/data/constants.js

@@ -134,6 +134,7 @@ export const TopicOrdering = {
 export const LearnersOrdering = {
   BY_FLAG: 'flagged',
   BY_LAST_ACTIVITY: 'activity',
+  BY_RECENCY: 'recency',
 };
 
 /**

src/discussions/learners/learner/LearnerFilterBar.jsx

@@ -103,6 +103,12 @@ function LearnerFilterBar({
                   selected={currentSorting}
                 />
               )}
+              <ActionItem
+                id="sort-recency"
+                label={intl.formatMessage(messages.recentActivity)}
+                value={LearnersOrdering.BY_RECENCY}
+                selected={currentSorting}
+              />
             </Form.RadioSet>
           </div>
         </Form>

src/discussions/learners/messages.js

@@ -38,6 +38,11 @@ const messages = defineMessages({
     defaultMessage: 'Reported activity',
     description: 'Text for learners sorting by reported activity',
   },
+  recentActivity: {
+    id: 'discussions.learner.recentActivity',
+    defaultMessage: 'Recent activity',
+    description: 'Text for learners sorting by recent activity',
+  },
   sortFilterStatus: {
     id: 'discussions.learner.sortFilterStatus',
     defaultMessage: `All learners by {sort, select,