(PDB-822) Change acceptance tests to incorporate structured facts.

This patch augments our basic_fact_retrieval and import_export acceptance tests
to include structured facts, and also bumps the version of the nodes query in
the facts/find indirector so structured facts are returned when puppet facts
find is issued to the PDB terminus.
With the v3 endpoint structured facts will be returned as stringified maps, so it's necessary if we want proper structured data in the output of facts/find.