feat(ui, builder): Option for 'add' methods on Maps and Lists

[ggranum]

Provide an option to allow users to enable addFoo methods for Collection fields.

For example, if I have:

public final List<Person> people;

the builder should gain the methods:

public Builder people(List<Person> people){ ... }
public Builder addToPeople(Person aPeople){ ... }

Super extra credit would be to add an annotation to the public field to allow setting the addFoo naming.