Add custom validations for each field of the APD model

[tbolt]

In order to support the upcoming admin check feature, we will need to add custom validations to the APD mongo/mongoose model

This task is done when...

• [ ] Every field/attribute in the model has an associated custom validation
• [ ] Each validation returns a message that will be shown when it fails

---

Add additional labels (design, dev, compliance, BUG, etc) and size before submitting.

If the issue is needed to complete prioritized work for the CURRENT SPRINT, add it to the "This Sprint" pipeline. Otherwise, all other issues will be automatically added to the unprioritized pipeline for prioritization in backlog refinement or sprint planning with Product.

[thetif]

OBE by adding joi validation that can be reused on the backend