Calculation update for "Deaths" widget in targets: CHT reference app

[ranjuts]

This ultimately updates the calculation for the Deaths widget, however, might require a config update as detailed below:

We need to not count stillbirths in this count (Deaths). That may require us updating the form config (delivery form) to either include whether or not the deceased baby was stillborn in baby's person record or not create the person record when its a stillbirth.

Preference is to not create a person record when its a stillbirth, however, if its easier technically to create the record regardless and mark as stillbirth that should be okay too.

@nomulex