api: add journalist first name, last name to token response

[redshiftzero]

Status

Ready for review

Description of Changes

Towards freedomofpress/securedrop-client#575

Changes proposed in this pull request:

• Simply adds the journalist first name and last name on the token response such that another round trip is not needed to fetch them on the client side.

Testing

You can follow the steps in securedrop-client PR here to test the server, SDK, and client side changes together: freedomofpress/securedrop-client#605

Deployment

deployed via securedrop-app-code package

Checklist

If you made changes to the server application code:

• Linting (make lint) and tests (make test) pass in the development container

If you made non-trivial code changes:

• I have written a test plan and validated it for this PR

If you made changes to documentation:

• Doc linting (make docs-lint) passed locally

[rmol]

Looks good to me. Ran through the test plan in freedomofpress/securedrop-client#605 successfully.