Add role cloning functionality and adjust permission methods.

Introduced a method to clone groups with their permissions and added a corresponding API endpoint for role cloning. Adjusted existing permission methods to ensure consistent behavior and naming, swapping the implementation of add/remove permissions. Improved permission fetching logic for cleaner data handling.

services/nginx/app/objects/groups_permissions_o.php

@@ -114,9 +114,14 @@ class groups_permissions_o extends db
      */
     public function getGroupPermissions(int $group_id): array
     {
-        return self::getFieldsWhere([
+        $raw_permissions = self::getFieldsWhere([
             'group_id' => $group_id
         ], ['permission']);
+        $permissions = [];
+        foreach ( $raw_permissions as $permission ) {
+            $permissions[] = $permission['permission'];
+        }
+        return $permissions;
     }
 
     /**