Organize projects in groups, and show each project only once (with version dropdown)

The enhancement may already be reported! Please search for the enhancement before creating one.

### Current Behavior:
In larger organizations the `Projects` list gets very long. And a single project is listed many times, with one entry per version.

### Proposed Behavior:
It would be helpful to introduce `Project Groups` in the `Projects` view. These groups could represent a self contained system or any other structure, and contain a bunch of projects.

So the structure would for example be

"Big self contained system" (`Project Group`)
> microservice A (`Project`)
> microservice B (`Project`)
> microservice C (`Project`)

And it would be great if each project would be shown only once, and not per version.
The projects list could per default show the latest version of a project, and other versions could be selected via dropdown.

Best regards,
Michael