Enabling/disabling inputs

[ashleybot]

Enhances validation and ui behavior (aka. enabling/disabling inputs, also called form logic).

Validation hierarchy

• Some validation, such as range validation should run no matter the form status
• However, required and required if properties should only fire validation if the form is attempting to be completed (aka. status = Complete)
• Only optional forms can be saved with a status of 'Not included' and in that case the reason code is required.
• Some forms have a different set of required fields for the initial visit vs follow-up visits. This validation is handled in the IsValid method rather than as an attribute.

Forms with behaviors

These forms are implemented:

• [x] A1
• [x] A4
• [x] B1
• [x] B4
• [x] B5
• [x] B6
• [x] B7
• [x] B8
• [x] C2

These forms still need to be done:

• [ ] A2
• [ ] A3
• [ ] A5
• [ ] B9
• [ ] C1
• [ ] D1
• [ ] D2

[ashleybot]

@smiththay This is a huge PR, so it will take you at least 1 day. Ideally, you'd to compare each of the completed forms against the current UDS app UI behavior. Where they differ, reference the official NACC documentation to determine which is correct.