MARC Remove Fields permissions too restrictive

[Bill Erickson]

The pcrud 'retrieve' permissions for vandelay::import_bib_trash_fields and vandelay::import_bib_trash_group are too restrictive for regular staff use. As it stands, you need edit permissions to view the options.

Branch forthcoming which makes these publicly visible. I'll avoid using STAFF_LOGIN, since some staff may be limited to STAFF_LOGIN at specific org units, which would prevent them from viewing trash group data at higher org units. (Note, the UI already does org unit filtering to ensure only trash group data at the workstation is retrieved).

[Bill Erickson (berick)]

working => user/berick/lp1190305-marc-remove-fields-perms

[Ben Shum (bshum)]

Looks good, thanks Bill! Picked to master and rel_2_4.