(PDB-4310) Fix intermittent unusual-queue-names test failures
(PDB-4310) Fix intermittent unusual-queue-names test failures

Unmake my mess.  Fix intermittent test failures in
handling-commands-producing-unusual-queue-names-across-restart which
I believe were caused by redef races across the server restart and/or
redefing at too low a level (move the redef to process-cmdref to
bypass all of the processsing, discards, etc.).

Rework the test to use two completely separate instances with a shared
vardir to make the phase separation simpler and hopefully clearer.

puppetlabs/puppetdb,puppetlabs/puppetdb,puppetlabs/puppetdb,puppetlabs/puppetdb,puppetlabs/puppetdb