MDL-61899 tool_dataprivacy: Fixes during integration review

* Disable tool by default.
* Add format columns for 'comments' and 'dpocomment' fields in
tool_dataprivacy_request table.
* Use data request exporter when sending email notification to DPO

admin/tool/dataprivacy/classes/data_request.php

@@ -56,6 +56,16 @@ class data_request extends persistent {
                 'type' => PARAM_TEXT,
                 'default' => ''
             ],
+            'commentsformat' => [
+                'choices' => [
+                    FORMAT_HTML,
+                    FORMAT_MOODLE,
+                    FORMAT_PLAIN,
+                    FORMAT_MARKDOWN
+                ],
+                'type' => PARAM_INT,
+                'default' => FORMAT_PLAIN
+            ],
             'userid' => [
                 'default' => 0,
                 'type' => PARAM_INT
@@ -88,6 +98,16 @@ class data_request extends persistent {
                 'type' => PARAM_TEXT,
                 'null' => NULL_ALLOWED
             ],
+            'dpocommentformat' => [
+                'choices' => [
+                    FORMAT_HTML,
+                    FORMAT_MOODLE,
+                    FORMAT_PLAIN,
+                    FORMAT_MARKDOWN
+                ],
+                'type' => PARAM_INT,
+                'default' => FORMAT_PLAIN
+            ],
         ];
     }
 }