api/raw: Ensure to ignore display names in raw object endpoint
The sha1 hash from the returned raw manifest for revision and release might differ from object id otherwise.
Related to #4226 (closed)
Test Plan
I tried to add a test for this but the sync_mailmap
django command
works only for postgresql storage and the webapp tests use a memory
storage so we cannot setup mailmaps here.
Migrated from D7804 (view on Phabricator)