This UI enables the user to set can_manage_group setting to a
combination of users and groups, replacing the old dropdown UI
which just allowed setting user to a single system group.
Fixes part of #28808.
This commit adds a group level setting can_manage_group in
`#groups` overlay. This setting can be set while creating a
new user_group and can be changed for existing groups.
Sahil Batra
Ujjawal Modi