Add GET endpoint for single approval fetch
Description
Develop {{GET /approvals/
{ref-id}/{approval-id}}} endpoint to return specific approval data.----
h4. Acceptance Criteria
Endpoint format is {{GET /approvals/{ref-id}
/
{approval-id}}}.
Develop {{GET /approvals/
{ref-id}/{approval-id}}} endpoint to return specific approval data./
{approval-id}}}.