Unify user and admin group creation form

Currently, the project creation form is unified. Whether you're a user clicking 'New Project' on the dashboard, or an admin clicking 'New Project' in the admin area, you're taken to /projects/new.

It seems reasonable that the group creation form could also be unified. Currently, there is a discrepancy between the two forms - one allows to check/uncheck the 'Request access' feature. Unifying them will prevent this sort of bug in the future.