Inline command send-receive code
Inline command send-receive code

Because commands only expect single documents, we can optimize
versus the more generic _query_and_receive that expects 1+ documents
in the response.

dagolden/mongo-perl-driver,mongodb/mongo-perl-driver,dagolden/mongo-perl-driver,xdg/mongo-perl-driver,mongodb/mongo-perl-driver,dagolden/mongo-perl-driver,xdg/mongo-perl-driver,mongodb/mongo-perl-driver,xdg/mongo-perl-driver,dagolden/mongo-perl-driver