Data model for organization-specific trainings and document submittals

## Dependency
Need to reassess if this requirement was met by finalizing high level DB schema per Tyler's comment: https://github.com/hackforla/HomeUniteUs/issues/360#issuecomment-2045949336
#

### Overview
Design data model to support organization-specific trainings and document submittals within the Home Unite Us application process.

### Action Items
Solidify a data model and specify the implementation requirements. Include considerations for the following:

### Resources/Instructions
* a document submittal or training step may have one or more prerequisite steps
* when multiple prerequisites are specified, they must be aggregated with either of the following conditions:
* at least one of the prerequisites is met
* all of the prerequisites are met