Poc lambda subhosting (#10192)

Add `SERVERLESS_LAMBDA_SUBHOSTING_ROLE` to allow hosting lambdas in
separate aws account

Tested with old configuration and new configuration

package.json

@@ -5,6 +5,7 @@
     "@apollo/server": "^4.7.3",
     "@aws-sdk/client-lambda": "^3.614.0",
     "@aws-sdk/client-s3": "^3.363.0",
+    "@aws-sdk/client-sts": "^3.744.0",
     "@aws-sdk/credential-providers": "^3.363.0",
     "@blocknote/mantine": "^0.22.0",
     "@blocknote/react": "^0.22.0",