Works cannot be saved if embargo or lease is assigned (nurax-pg)

[eporter23]

Descriptive summary

Using Hyrax 3.3/Nurax-pg, a user cannot save a new work or save changes to an existing work if an embargo has been assigned.

Rationale

Users should be able to assign embargoes if they are enabled for a given Admin Set.

Expected behavior

If a user can select embargo options, they can then populate them and save their changes to the work.

Actual behavior

When an embargo is assigned to a work, clicking Save returns the following error: Failed save on # undefined method `[]' for nil:NilClass

Steps to reproduce the behavior

1. Create a new work or edit an existing work in an Admin Set that allows embargoes/leases (e.g. Default Admin Set)
2. Select any permitted embargo or lease option (e.g. Embargo > Restricted to Private until 3/30/2023; then open to Public)
3. Make sure all Requirements show green checks under Save Work
4. Click Save Changes
5. See error message in banner above the work form

Related work

Prior work: #5460