MHR API - Retrieve rejection report from DRS API via MHR Api

New MHR API wrapper call to retrieve a rejection report pdf from the DRS API.
- Use the mhr_registrations_report table new drs_id column value to retrieve the document either as binary data or a download link
- Use a SA token (with the SYSTEM role) when submitting the DRS API request GET /doc/api/v1/searches/MHR?documentServiceId={drs_id}.

Locate the MHR API wrapper entry point and the mhr_registrations_report table or schema; start by tracing how the new drs_id value is stored and how existing DRS API calls authenticate. Verify GET /doc/api/v1/searches/MHR?documentServiceId={drs_id} with a SYSTEM-role SA token, and consider the work done when the rejection report is returned as binary data or a download link.

Written by the indexing model from the issue text.