feat: manage database/user/grants for patroni

- add defines for exporting/collecting psql objects for patroni
- add generic profile for managing patroni psql databases for an app

site/profiles/manifests/sql/postgres/db.pp

@@ -0,0 +1,9 @@
+define profiles::sql::postgres::db (
+  String $dbname,
+) {
+  postgresql_psql { "create_database_${dbname}":
+    command => "CREATE DATABASE \"${dbname}\"",
+    unless  => "SELECT 1 FROM pg_database WHERE datname = '${dbname}'",
+  }
+}
+