API endpoint to list the packages of a group

Merged David Fernandez requested to merge 10003-api-endpoint-to-list-the-packages-of-a-group into master

What does this MR do?

This MR adds a new packages API method to list packages at group level.

We have a similar method at the project level.

This MR will use the existing finder to get all packages within the given group. Subgroups are included by default as requested by #10003 (comment 238527899).

See #10003 (closed)

Screenshots

The updated documentation should give a pretty good idea of how this API method works.

Does this MR meet the acceptance criteria?

Conformity

Availability and Testing

Security

If this MR contains changes to processing or storing of credentials or tokens, authorization and authentication methods and other items described in the security review guidelines:

  • Label as security and @ mention @gitlab-com/gl-security/appsec
  • The MR includes necessary changes to maintain consistency between UI, API, email, or other methods
  • Security reports checked/validated by a reviewer from the AppSec team
Edited by David Fernandez