Resolve ""Usage quota" button for subgroup leads to 404"

What does this MR do?

It hides the Usage Quotas link from the side bar in sub-groups, the link was pointing to a blank 404 page.

Note: I'm not 100% sure that the view usage is limited to the top level groups only and whether it should be applied to the sub-groups also. In case the view usage is not limited to top level groups and should be applied to sub-groups, another follow up issue should be created to revert this merge request and fix the dead link.

Closes #13629 (closed)