INCLUDE IDs - where to add them, how to refer to them

[lopierra]

The model currently has fields for participantExternalID (generated by data contributor) and participantId (to be generated by CHOP).

1. Do we need similar external/internal distinctions for sample and file IDs, and if so, which specific levels of sample (Collection, Parent Sample, Sample, Container)? We have received both Sample and Container IDs from contributors thus far.
2. I will change participantId to be NOT required for now, as it's unclear when in the process the IDs will be generated.
3. For March, we will refer internally to external IDs. Open to changing this post-March depending on the workflow for internal ID generation.

Please respond with feedback/suggestions and indicate whether they are for March (priority) or post-March.

[lopierra]

Decision for March: see changes here. Basically adding internal and external ID fields for each level of Biospecimen.