Upgrade Nextcloud setup to use compose files

- Integrated MariaDB role into Dockerbox configuration
- Moved proxy role to the end to avoid early endpoint activation
- Temporarily disabled select roles for future re-evaluation
- Introduced flush_handlers task for early MariaDB restart
- Moved a few Nextcloud tasks to handlers
- Configured Nextcloud to utilize the host's MariaDB instance
- Enhanced overall code linting quality

roles/nextcloud/defaults/main.yml

@@ -1,11 +1 @@
-# container names
-nextcloud_container: nextcloud
-nextcloud_dbcontainer: "{{ nextcloud_container }}-db"
-
-# database settings
-nextcloud_dbname: "{{ nextcloud_container }}"
-nextcloud_dbuser: "{{ nextcloud_dbname }}"
-
-# host mounts
-nextcloud_root: "/opt/{{ nextcloud_container }}/public_html"
-nextcloud_dbroot: "/opt/{{ nextcloud_container }}/database"
+nextcloud_name: nextcloud