Add a new team management endpoint

[suricactus]

Currently QFieldCloud offers REST-like APIs for management of project collaborators and organization members. The management includes the users and their roles.

One of the key functionalities in QFieldCloud UI is the team management that allows grouping organizatio members in respective teams and giving the teams access to specific projects with respective roles.

Unfortunately the team management API is only available via Admin UI and not like the REST-like API.

This feature requests insists on the need to add such team management REST-like API, similar to project collaborators and organization members API, ensuring one can list, create and delete a team with respective role, as well as update the role of already created team.

Related documentation:

https://docs.qfield.org/reference/qfieldcloud/concepts/
https://app.qfield.cloud/swagger/#/api/api_v1_collaborators_list