Allow psql args to be given to matrix-postgres-cli

This passes any arguments given to 'matrix-postgres-cli' to the 'psql' command.

Examples:
  $ # start an interactive shell connected to a given db
  $ sudo matrix-postgres-cli -d synapse
  $ # run a query, non-interactively
  $ sudo matrix-postgres-cli -d synapse -c 'SELECT group_id FROM groups;'

roles/matrix-postgres/templates/usr-local-bin/matrix-postgres-cli.j2

@@ -9,4 +9,5 @@ docker run \
 	--env-file={{ matrix_postgres_base_path }}/env-postgres-psql \
 	--network {{ matrix_docker_network }} \
 	{{ matrix_postgres_docker_image_to_use }} \
-	psql -h {{ matrix_postgres_connection_hostname }}
+	psql -h {{ matrix_postgres_connection_hostname }} \
+	"$@"