self_html link in community requests is wrong

[tmorrell]

Package version (if known): v12

Describe the bug

The self_html link in a requests API results in a 404 because it is missing the community path. Example https://inveniordm.web.cern.ch/api/requests/52636814-f66c-4330-b9ed-5e15ee1eda80 has self_html: "https://inveniordm.web.cern.ch/requests/52636814-f66c-4330-b9ed-5e15ee1eda80". Working links are either https://inveniordm.web.cern.ch/me/requests/52636814-f66c-4330-b9ed-5e15ee1eda80 or https://inveniordm.web.cern.ch/communities/testing/requests/52636814-f66c-4330-b9ed-5e15ee1eda80

Steps to Reproduce

1. Create a community submission
2. Got to /api/requests/ with the request id
3. Click on the self_html link
4. See error

Expected behavior

The /me/requests/ path seems like a easier fix, though it might not work for individuals with just community permissions.

Screenshots (if applicable)

Additional context