Allow reading payload parameters from secret / parameter store

In case of authorization headers needing to be sent to HTTP(s) endpoint - they should be stored in secret store, rather than passed unencrypted as payload to lambda function. Suggestion is that if any value in payload is in following forms
- `aws:smps("path")`
- `aws:sm("store.key")`

They should be replaced with actual secret value from AWS System Manager Parameter Store (first form), or AWS Secrets Manager (2nd form).

No files or tests are named in the issue. Start by locating the Lambda payload handling and AWS configuration, then trace how values are sent to the HTTP endpoint. Done means payload values using both specified forms are resolved from the corresponding AWS store before the request is made, without exposing the secrets in the payload.

Written by the indexing model from the issue text.