Sub-projects support in UpMan
Description
The background of the requirement is to reduce the workload on the main Unity Admin, who currently has to manually define all projects enabled for UpMan. The idea is to allow the project admin to also "re-delegate", i.e. create delegated projects from UpMan, using subgroups of the active project as roots.
To realize this we need:
two new extra role values (settable by the main unity admin on projects admin): allow-to-re-delegate and allow-to-redelegate-recursive
in upman (only for ppl with the permission from the point above) add an option to delegate subgroup management separately (as a sub project).
in upman allow for controlling sub-project admins (what is separate from the main project admin). This should allow for setting two types of sub-admin: with redelegation possible or not. Of course redelegation option should be possible only if current project manager has the rights to re-delegate.
internally we would need to take care of deriving all forms for the sub project from the main project forms
