Groups of organizations

[marien-probesys]

Problem

In the context of #516, we're deprecating the sub-organizations. But we still need an alternative to be able to declare shared configurations options (e.g. templates, categories, etc.)

Solution

We introduce the groups of organizations. Groups allow to mark several organizations with similarities. For instance, organizations can be grouped according to the team who is in charge of the organizations. Groups will allow later to share common configurations options, such as categories, templates, etc.

Specifications

• (technical debt) Transform the organization form with the Symfony Form component (related to Refactor forms with the Symfony Form component #551)
• Create a new permission to manage groups of organizations in the admin (admin:manage:orga_groups)
• Add a section in the administration to list groups of organizations
• Add an input in the organization form to select one or several groups
• Display the groups of the organizations in the list of organizations, in the organizations cards on the home page and on the organization page
• Allow to list the organizations of a group
• Allow to edit/delete a group
• Create a special group that cannot be removed and attached to all the organizations, named "Common" (make sure organizations cannot be detached from it)

Control

1. Login with a user which has the permission to manage groups of orga
2. Check that you can access the list of groups in the admin
3. Check that the "Common" group exists, and that you cannot edit/delete it
4. Check that you can create, edit and delete a group
5. Make sure to have a group (different than "Common")
6. Edit an organization and attach it to the group
7. Check that you see the group of the organization on its page, in the list of organizations and on the home page
8. Check that you can see the organizations of a group on its page