feat: Add Metabase as a new service

Adds the Metabase service to the Docker Compose setup.

- Creates a compose.yaml and .env.example for Metabase.

- Adds Metabase to the list of deployed services in the Ansible configuration.

- Updates .gitignore

docker_compose_applications/metabase/.env.example

@@ -0,0 +1,6 @@
+MB_DB_TYPE=postgres
+MB_DB_DBNAME=metabase
+MB_DB_PORT=5432
+MB_DB_USER=metabase
+MB_DB_PASS=changeme
+MB_DB_HOST=your-postgres-host