Using a named role for the lambda, such as `nasa-veda-prod`, should be possible in cdk code

For the dev VEDA titiler deployment, I am using the `nasa-veda-prod` role in the SMCE VEDA account for access to different datasets, since this role has been provided to some DAACs and (I believe but need to double check) has access to VEDA buckets.

Right now the role itself should be able access all S3 buckets (ie not a whitelist of buckets). So it should be able to access any bucket which has whitelisted that role in the bucket policy.

I made the change to the lambda's role in the AWS console and it should be possible to specify a role for the lambda in the CDK code.