Translate from pom.xml and codemeta.json.

Summary:
Also changes slightly the output format to provide
a @type and make it more compact.

Resolves T1289.

Test Plan: tox

Reviewers: moranegg

Reviewed By: moranegg

Subscribers: swh-public-ci

Maniphest Tasks: T1289

Differential Revision: https://forge.softwareheritage.org/D620