Add support for querying raw-extrinsic-metadata for origins
It is purposefully discouraged to query the api-1-raw-extrinsic-metadata-swhid endpoint directly, as extended SWHIDs should not be part of the public API.
Instead, clients should query api-1-origin first, and rely on the link in its response to fetch metadata.
Migrated from D8114 (view on Phabricator)