Split `name` into `first_names`, `last_names`

[todrobbins]

Some folks have noted that sorting by first name is not very useful, so let's split the name field in candidates.yml into two fields:

• first_names: e.g. 'John Samuel'
• last_names: e.g. 'Smith Jr.'

We'll need to update a few templates as well with the new fields.

[todrobbins]

@ccallowheusser is this you're still interested in hacking on or should I move forward?

[todrobbins]

resolved via previous commits