Group based Maven API endpoint

Repositories should also be available at the group level. This has a number of benefits, including:

• Easier interaction for users, with a single repository containing of your packages
• Projects that depend upon the repository output of other sister projects is easier to manage, without having to worry about cross-project access tokens

Proposal

• repositories endpoint is available at group level: /groups/group_name/-/packages/maven

Open questions

• Access control for publishing into these repositories. All child projects?