ARGO-302: add support for renamed DOR-wide roles: dlss:dor-admin -> sdr:...

...administrator-role, dlss:dor-manager -> sdr:manager-role, dlss:dor-viewer -> sdr:viewer-role

sorry, that wasn't the best commit message, in retrospect.  what actually got renamed here are the "dor-administrator" and "dor-viewer" roles that are defined in APOs (and which list workgroups/users), so that the APO role names would better correspond with the new workgroup names.  since both workgroup namings still exist at present (with the dlss:dor- groups as aliases for the new sdr: groups), this code change adds support for the new group names while leaving support for the old group names in place for now.  when the old names no longer exist, we can pull support for them.