feat(backend-defaults): add AWS RDS IAM authentication support for PostgreSQL

Signed-off-by: Roland Fuszenecker <roland.fuszenecker@seon.io>

packages/backend-defaults/package.json

@@ -130,6 +130,7 @@
     "@aws-sdk/client-codecommit": "^3.350.0",
     "@aws-sdk/client-s3": "^3.350.0",
     "@aws-sdk/credential-providers": "^3.350.0",
+    "@aws-sdk/rds-signer": "^3.0.0",
     "@aws-sdk/types": "^3.347.0",
     "@azure/identity": "^4.0.0",
     "@azure/storage-blob": "^12.5.0",