Currently we can't set server groups and server group members quotas
in Horizon, they are still the back end definition of default.
In some cases, it will failed to create an instance when server group
members quota is insufficient. Therefore, it is necessary to specify
the quota of the server groups and server group members when creating
and editing the project. This patch allows the user to modify the
default values for the server groups and the server group members
quota.
Change-Id: Ifbd51bec3e775d8fecbf110da37309a443a3d1ba
Closes-Bug:#1732429
e0e81e2b87