Update set_acl_package

One should be able to assign ACLs to himself if the package is orphaned for this branch
Fix checking if the packager is a poc or a co-maintainer
Add the possibility to give the PoC to someone else

This also fix the setting of the ACLs to the person that request an orphan package via
the UI.
Expand the get_acl_package method to filter the ACLs returned to a specific collection
Add an un-orphan method which change status and gives appropriate ACLs to new poc
Change back set_acl_package to not allow someone to set ACLs to himself/herself
Fix UI and API to rely on the new unorphan package method
Expand test on the get_acl_package function to cover filtering by collection
Add unit-test to the unorphan method