server: the method for associating/attaching response headers from Hasura

### Is your proposal related to a problem?

Configuring custom response headers from Hasura is not possible in the current implementation. Use case could be - attaching security headers to the responses (sent from Hasura).

### Describe the solution you'd like

If there's a workaround or any solution which can be done outside Hasura, that would be grateful.

### Describe alternatives you've considered

I haven't thought much, but would it be possible if user is using [authentication with webhook](https://hasura.io/docs/latest/auth/authentication/webhook/). That way if we can use webhook as middleware , but I don't have proof of if there's a way to attach response headers on the fly from webhook handler.

The issue names no file, test, or entry point. Start by tracing how Hasura server responses are produced and checking whether authentication webhooks expose a response-header path; done requires a confirmed supported approach or a clearly scoped implementation proposal.

Written by the indexing model from the issue text.