REFACTOR(vault): update Vault secret paths

- Update secret paths for databases/*
- Reorganize secret structure

postgresql/vault/postgresql-password.yaml

@@ -14,13 +14,13 @@ spec:
   data:
     - secretKey: password
       remoteRef:
-        key: postgresql/root
+        key: databases/postgresql
         property: PASSWORD
     - secretKey: postgres-password
       remoteRef:
-        key: postgresql/root
+        key: databases/postgresql
         property: POSTGRES_PASSWORD
     - secretKey: replication-password
       remoteRef:
-        key: postgresql/root
+        key: databases/postgresql
         property: REPLICATION_PASSWORD