Add more functions to the chef_object behavior

This covers:

* authz_id
* ejson_for_indexing
* update_from_ejson
* set_created
* set_updated

And new callbacks for chef_db integration that name the prepared query
for the object:

* create_query
* update_query
* delete_query
* find_query
* list_query
* bulk_get_query

These will allow us to share boilerplate code for interacting with the
db, but keep the db code and this code decoupled in terms of being
direct dependencies.