Make the collection list available with 'GET Col-IRI'
- Follows the AtomPub https://datatracker.ietf.org/doc/html/rfc5023\#section-5.2\ spec
- Discoverable from the service document
- Makes more sense semantically to have the list of items in a path at the root of that path.
Related to #2996 (closed)
Migrated from D5778 (view on Phabricator)