Create top level view of shared groups.

Proposal

Groups and projects invites with groups have impact on seat usage but currently is not easy to view what groups are being shared where.

The only current way is to use the API to list inherited members

This issue suggest to create a top level view, at the root level that shows what groups and projects are invited to the sub groups.

A better version of the table below can work.

Subgroup	Invited group
Subgroup1	External group
SubGroup2	External project