Add Death Date breakdowns

[nanthony007]

@cdelcher suggests adding the following breakdown fields using the death date:

• death month
• death year
• death week (of year)
• is_weekend

This will require modifying configuration so that user's provide the correct column to pull this information from.

Before working on, validate that all three principal datasets have death date time fields.

[nanthony007]

The MIL dataset has deathdate, the other two datasets have death_date