API: Add support for repository management

[chouseknecht]

• [ ] Enable admins to create, update and delete repositories.
• [ ] Support two repository types: sync and modify. Sync repositories pull content in from an external AH instance (e.g., Community Hub, AH Cloud, another private AH) and are read only. Modify repositories can be used for CLI publish and promote operations.
• [ ] Expose repositories via URL path. For example, to publish a collection to repository-a, a user would publish to /api/v3/repository-a/artifacts/collections.

[bmbouter]

Call sync with: https://pulp-ansible.readthedocs.io/en/latest/restapi.html#operation/repositories_ansible_ansible_sync

Call modify with: https://pulp-ansible.readthedocs.io/en/latest/restapi.html#operation/repositories_ansible_ansible_modify

Create a repository with: https://pulp-ansible.readthedocs.io/en/latest/restapi.html#operation/repositories_ansible_ansible_create

Create a Remote for syncing collection type content here: https://pulp-ansible.readthedocs.io/en/latest/restapi.html#tag/remotes:-collection

Create a Remote for syncing role content here: https://pulp-ansible.readthedocs.io/en/latest/restapi.html#operation/remotes_ansible_ansible_create

Create a Distribution (with it's "base_path") here: https://pulp-ansible.readthedocs.io/en/latest/restapi.html#operation/distributions_ansible_ansible_create and you can see url the client should use as the "client_url" field on it. You can point it at a Repository or RepositoryVersion and it will serve that content.