Add form to organization group edit page

What does this MR do and why?

Related to #410810 (closed)

The grouptenant scale team is starting to build out an Organization MVC. For more information about what an "Organization" will be see https://docs.gitlab.com/ee/architecture/blueprints/organization/

We are building a page to edit a group at the organization level. In !152867 (merged) we setup the route, controller, and basic Vue app. This MR sets up the form. The form is not yet hooked up to the API, to keep the MR smaller and easier to review that will be setup in a future MR.

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Screenshots or screen recordings

Mobile	Desktop

How to set up and validate locally

1. Enable the feature flag
   • echo "Feature.enable(:ui_for_organizations)" | gdk rails c
2. Navigate to /-/organizations/default/groups_and_projects
3. Choose a group, click the actions dropdown and select Edit