Import DataGeneration and DataObject classes from nmdc-schema

[aclum]

This ticket is to update the process of importing classes from nmdc-schema to include DataGeneration and DataObject into submission-schema and making needed modification (ex making url required).

[aclum]

We will need 4 classes, will need to track analysis type in the external UI tab so we know what data objects go with which data_generation_set records.