DEV: Switch over category settings to new table - Part 3 (#20657)

In #20135 we prevented invalid inputs from being accepted in category setting form fields on the front-end. We didn't do anything on the back-end at that time, because we were still discussing which path we wanted to take. Eventually we decided we want to move this to a new CategorySetting model.

This PR moves the require_topic_approval and require_reply_approval from custom fields to the new CategorySetting model.

This PR is nearly identical to #20580, which migrated num_auto_bump_daily, but since these are slightly more sensitive, they are moved after the previous one is verified.

db/migrate/20230910021213_update_category_setting_approval_values.rb

@@ -0,0 +1,74 @@
+# frozen_string_literal: true
+
+class UpdateCategorySettingApprovalValues < ActiveRecord::Migration[7.0]
+  def up
+    change_column_default :category_settings, :require_topic_approval, false
+    change_column_default :category_settings, :require_reply_approval, false
+
+    execute(<<~SQL)
+      WITH custom_fields AS (
+        SELECT
+          category_id,
+          MAX(
+            CASE WHEN (name = 'require_topic_approval')
+            THEN NULLIF(value, '') ELSE NULL END
+          )::boolean AS require_topic_approval,
+          MAX(
+            CASE WHEN (name = 'require_reply_approval')
+            THEN NULLIF(value, '') ELSE NULL END
+          )::boolean AS require_reply_approval,
+          NOW() AS created_at,
+          NOW() AS updated_at
+        FROM category_custom_fields
+        WHERE name IN (
+          'require_topic_approval',
+          'require_reply_approval'
+        )
+        GROUP BY category_id
+      )
+      INSERT INTO
+        category_settings(
+          category_id,
+          require_topic_approval,
+          require_reply_approval,
+          created_at,
+          updated_at
+        )
+      SELECT * FROM custom_fields
+      ON CONFLICT (category_id) DO
+      UPDATE SET
+        require_topic_approval = EXCLUDED.require_topic_approval,
+        require_reply_approval = EXCLUDED.require_reply_approval,
+        updated_at = NOW()
+    SQL
+
+    execute(<<~SQL)
+      UPDATE category_settings
+      SET require_topic_approval = false
+      WHERE require_topic_approval IS NULL;
+    SQL
+
+    execute(<<~SQL)
+      UPDATE category_settings
+      SET require_reply_approval = false
+      WHERE require_reply_approval IS NULL;
+    SQL
+  end
+
+  def down
+    change_column_default :category_settings, :require_topic_approval, nil
+    change_column_default :category_settings, :require_reply_approval, nil
+
+    execute(<<~SQL)
+      UPDATE category_settings
+      SET require_topic_approval = NULL
+      WHERE require_topic_approval = false;
+    SQL
+
+    execute(<<~SQL)
+      UPDATE category_settings
+      SET require_reply_approval = NULL
+      WHERE require_reply_approval = false;
+    SQL
+  end
+end