feat: Add Admin Groups Management Module

- Introduced a new module for managing user groups (`usrgrp`) in the administration interface.
- Implemented CRUD operations for user groups: list, create, rename, and delete.
- Added authorization checks to ensure only users with appropriate permissions can manage groups.
- Created corresponding frontend JavaScript and SCSS files for the new module.
- Updated documentation to reflect the new group management functionality and its authorization model.
- Added SQL stored procedures for group management operations.
- Established a new login script for database access, ensuring proper security practices.

Fuchs/js/intranet/fis_texts_gui_de.js

@@ -7,6 +7,7 @@
     , m_admin: 'Administration'
     , m_admin_status: 'Systemüberwachung'
     , m_usr: 'Benutzerverwaltung'
+    , m_usrgrp: 'Gruppenverwaltung'
     , rsp: 'Passwort ändern'
     , pnm: 'Die Passwörter stimmen nicht überein'
     , cps: 'Das neue Passwort wurde gespeichert.'