Get results specific to contact sender, recipient and broadcaster via the NationBuilder contact API

A recent update to the contact API extends the ability to index contacts. Additional parameters that can be used to index contacts include:

• author_id - the NationBuilder id of the contact sender
• person_id - the NationBuilder id of the contact recipient
• broadcaster_id - the id of the broadcaster on whose behalf the contact is logged

Please note that the sender_id and recipient_id will also be returned in the response body until those resources are deprecated.