API response for all projects a user has access to

Description

Premium customer would like to retrieve the data from GET admin/users/<user>/projects via the API.

They would also like the access level to be displayed.

Proposal

As proposed by @Andysoiron, we will add a new endpoint that returns all membership information that takes a variable (type) which can scope it to specific membership types.

GET user/:id/memberships

[
  {
    "source_id": "1111",
    "source_name": "EXAMPLE PROJECT",
    "source_type": "Project"
    "access_level": "PROJECT ACCESS LEVEL"
  },
  {
    "source_id": "123",
    "source_name": "EXAMPLE Group",
    "source_type": "Namespace"
    "access_level": "GROUP ACCESS LEVEL"
  }
[

user/:id/memberships?type=Project would only return project memberships and user/:id/memberships?type=Namespace would return only group memberships.

Links / references

ZD: https://gitlab.zendesk.com/agent/tickets/88949 (Internal only)