Survey attribute existance based on new vs. existing person

[cormander]

As a field organizer, I don't need to collect all the data points we have in a voter file when knocking the doors of non-voters, yet still want to see those data points on people already in the database, so that I have as much info as possible without bogging down the collection process for new people.

This feature is done when:

• Based on configuration, certain form attributes are hidden on the "Add Person" survey
• These form attributes still exist when looking at an existing person in the database