Refactor LDAP variable schema to use top-level constant LDAP and nested ALL-CAPS keys.

- Converted group_vars/all/13_ldap.yml from lower-case to ALL-CAPS nested keys.
- Updated all roles, tasks, templates, and filter_plugins to reference LDAP.* instead of ldap.*.
- Fixed Keycloak JSON templates to properly quote Jinja variables.
- Adjusted svc-db-openldap filter plugins and unit tests to handle new LDAP structure.
- Updated integration test to only check uniqueness of TOP-LEVEL ALL-CAPS constants, ignoring nested keys.

See: https://chatgpt.com/share/68b01017-efe0-800f-a508-7d7e2f1c8c8d

roles/svc-db-openldap/templates/docker-compose.yml.j2

@@ -10,12 +10,12 @@
 {% endif %}
     volumes:
       - 'data:/bitnami/openldap'
-      - '{{openldap_ldif_host_path}}:{{openldap_ldif_docker_path}}:ro'
+      - '{{openldap_ldif_host_path}}:{{ openldap_ldif_docker_path }}:ro'
     healthcheck:
       test: >
         bash -c '
         ldapsearch -x -H ldap://localhost:{{ openldap_docker_port_open }} \
-          -D "{{ ldap.dn.administrator.data }}" -w "{{ ldap.bind_credential }}" -b "{{ ldap.dn.root }}" > /dev/null \
+          -D "{{ LDAP.DN.ADMINISTRATOR.DATA }}" -w "{{ LDAP.BIND_CREDENTIAL }}" -b "{{ LDAP.DN.ROOT }}" > /dev/null \
         && ldapsearch -Y EXTERNAL -H ldapi:/// \
           -b cn=config "(&(objectClass=olcOverlayConfig)(olcOverlay=memberof))" \
         | grep "olcOverlay:" | grep -q "memberof"