Field selection as parameter

Allow the fields that are selected to be stored to be selected via a parameter. This will allow custom selection of which fields from the Google Maps results should be stored in the contact data.
Is it the standard to use `:` for namespacing? 

I also noticed that with the current code, using something like `geometry.bounds.northeast.lat` as a parameter won't work, so I will have to write code to deconstruct things like that.

How should I go about storing the object data? For instance, if they choose `geometry.bound.northeast.lat` as a parameter that they want to store, then it is an object containing `lat` and `lng`. Should I then store a stringify'd JSON object, or do we need to fully unpack the object and store it in separate fields?