Allow pbs_ralter to edit Authorized_Users and Authorized_Groups

Users want to be able to edit the authorized users and groups of a reservation.

Design can be found here: https://pbspro.atlassian.net/wiki/spaces/PD/pages/1515683901/Allow+pbs+ralter+to+edit+Authorized+Users+and+Authorized+Groups

Will you do any verification that the requested group is valid?