[Groups] Allow Groups to set Homepage

[hpalmersheim]

We have more schools using the admin- and course-level groups feature to communicate with staff in the building and differentiate by type of staff, grade level teams, departments and others.  It would be extremely beneficial if the group function allowed them to set a custom homepage.  If you go to the pages it does allow you to set a homepage but then the group home only shows the recent activity stream.

[jbay005]

Agreeing with @hpalmersheim et al! This is a long overdue request that needs to be actioned...