Remove format as a PI requirement

[ekemeyer]

Is your feature request related to a problem? Please describe.
Many of our born digital assets will not have a Physical instantiation format (instantiationPhysical), however it is required. The workaround has been to put a stand-in value to get records ingested. Ideally this should not be required.

Describe the solution you'd like
Remove instantiationPhysical as required from relevant batch ingesters (AAPB Core Zipped, AAPB CSV Ingester, AAPB CSV Physical Instantiation Ingester, AAPB PBCORE XML Instantiation Reset) and from manual record creation in the GUI.

Currently, without an instantiationPhysical value the ingests succeed, but the entire Physical instantiation is not included, creating missing children.

Describe alternatives you've considered
Putting "unknown" or other vague format in its place. However, there are thousands of existing records that need to be ingested (specifically through PBCore zipped ingester), and we want to avoid assigning fake formats to all of them.

[jillpe]

removing requirement = 2
Putting format in it's place = 2