[comm-lib] Verify CSAT in HTTP middleware

Summary:
Updated the HTTP middleware function to verify authorization credential, unless verification is disabled.

Depends on D12412, D12413

Test Plan: At this point, test plan from D12412 also requires credentials to be valid (token present in Identity).

Reviewers: varun, will, kamil

Reviewed By: varun

Subscribers: ashoat, tomek

Differential Revision: https://phab.comm.dev/D12414