Group Import fixtures

What does this MR do?

This MR is part of a bigger MR !19560 (closed) that introduces Group Import functionality (similar to Project Import what we have today). Mentioned MR is going to be split into multiple MRs in order to make it easier to review and merge.

This MR does not make any business logic changes, just adds 2 new group.json fixtures. So that later on when it comes to business logic updates and specs updates it does not cause additional load on reviewers (specifically because of LOC numbers).

complex/group.json has:

1. 10 labels
2. 5 group members
3. 1 badge
4. 5 milestones
5. 2 boards
6. 5 epics
7. 2 subgroups containing the same amount of relations

no_children/group.json has:

1. same as above but without subgroups

Screenshots

N/A

Conformity

• [-] Changelog entry
• [-] Documentation (if required)
• [-] Code review guidelines
• [-] Merge request performance guidelines
• [-] Style guides
• [-] Database guides
• [-] Separation of EE specific content

Availability and Testing

N/A

Security

N/A