[DATABASE] Update "modified" in Managed_DataObject instead of a DBMS trigger

Instead of relying on the MariaDB's ON UPDATE CURRENT_TIMESTAMP trigger update
"modified" attributes in Managed_DataObject. Every raw query that needs
adjusting is adjusted, as they won't update "modified" automatically anymore.

The main goal behind this change is to fix "modified" updates on PostgreSQL.

classes/Notice.php

@@ -3243,7 +3243,11 @@ class Notice extends Managed_DataObject
                         unset($notice);
                         $notice = new Notice();
                         $notice->query(sprintf(
-                            'UPDATE %1$s SET %2$s = NULL WHERE id IN (%3$s)',
+                            <<<'END'
+                            UPDATE %1$s
+                              SET %2$s = NULL, modified = CURRENT_TIMESTAMP
+                              WHERE id IN (%3$s)
+                            END,
                             $notice->escapedTableName(),
                             $field,
                             implode(',', $ids)