Currently project groups have a separate "edit" view, which makes it
hard to route to them by name. This commit changes this so that editing
is done in the detail view, as it is for other objects like Projects or
Stories, in order to facilitate routing by name.
Depends-On: https://review.openstack.org/#/c/590047/
Change-Id: I7f26838ce255268653cd2f912a4f7bb2a13d2816