pre-fix for dependency on UR bug

This currently depends on a bug in UR that will soon be fixed and will
then need to fall back onto Workflow::DataSource::InstanceSchema as a
consequence of our Postgres/Oracle syncing.
Let resource checks go through the instance before falling through to the type.  The adaptor for commands supports resolve_resource_requirements(), which can return either a string or object.
Merge branch 'master' of ssh://git/srv/git/workflow