FIX: Add 'Ignored' flags to Moderator Activity report (#22041)

* FIX Add 'Ignored' flags to Moderator Activity report

The Moderator Activity query didn’t include the number of deferred flags in the Flags Reviewed totals. As this number is designed to reflect how many flags a moderator has seen, reviewed, and made a judgement on, the Ignored ones should also be included.

* Apply suggestions from code review

---------

Co-authored-by: Jarek Radosz <jradosz@gmail.com>

app/models/concerns/reports/moderators_activity.rb

@@ -73,7 +73,8 @@ module Reports::ModeratorsActivity
       flag_count AS (
           WITH period_actions AS (
           SELECT agreed_by_id,
-          disagreed_by_id
+          disagreed_by_id,
+          deferred_by_id
           FROM post_actions
           WHERE post_action_type_id IN (#{PostActionType.flag_types_without_custom.values.join(",")})
           AND created_at >= '#{report.start_date}'
@@ -94,13 +95,23 @@ module Reports::ModeratorsActivity
           JOIN period_actions pa
           ON pa.disagreed_by_id = m.user_id
           GROUP BY disagreed_by_id
+          ),
+          deferred_flags AS (
+          SELECT pa.deferred_by_id AS user_id,
+          COUNT(*) AS flag_count
+          FROM mods m
+          JOIN period_actions pa
+          ON pa.deferred_by_id = m.user_id
+          GROUP BY deferred_by_id
           )
       SELECT
-      COALESCE(af.user_id, df.user_id) AS user_id,
-      COALESCE(af.flag_count, 0) + COALESCE(df.flag_count, 0) AS flag_count
+      COALESCE(af.user_id, df.user_id, def.user_id) AS user_id,
+      COALESCE(af.flag_count, 0) + COALESCE(df.flag_count, 0) + COALESCE(def.flag_count, 0) AS flag_count
       FROM agreed_flags af
       FULL OUTER JOIN disagreed_flags df
       ON df.user_id = af.user_id
+      FULL OUTER JOIN deferred_flags def
+      ON def.user_id = af.user_id
       ),
       revision_count AS (
       SELECT pr.user_id,