A5 Arthritis questions validation

[ashleybot]

There are several variables defining arthritis history in the A5 (ARTHRIT, ARTHTYPE, ARTHTYPX, ARTHUPEX, ARTHLOEX, ARTHSPIN, ARTHUNK). Health history is only complete during initial visits.

We have some validation to shore up with these arthritis questions:.

• [x] Use bool type in view model to simplify bindings. (Checkboxes are really a lot simpler for a non-nullable boolean.)
• [x] If ARTHRIT is 1 or 2 then ARTHTYPE is required
• [x] If ARTHTYPE is 3 (Other) then ARTHTYPX is required
• [x] Regions affected (ARTHUPEX, ARTHLOEX, ARTHSPIN, ARTHUNK) are not required

Reference

• https://files.alz.washington.edu/documentation/uds3-ivp-ded.pdf
• https://files.alz.washington.edu/documentation/uds3-ivp-guidebook.pdf

[ashleybot]

There is already a draft PR and feature branch to kick-off this card. Please build upon it.