Add missing import
Eliminate calculated property
Let ModelPair generate combination_label
Cache dag and eliminate is_valid check

Turns out that __errors__ gets the values of transient_optional
properties and this leads to premature caching.
f combination-label
Use TestHelper to check dag xml
f ModelPair combination label
Extract get_models_for_roi method
Remove output_dir as input from Trio
Use TestHelper to test dag xml
Get Trio Wrapper DAG produced properly
Ensure is_many property is passed an array_ref
Allow UR objects as workflow_inputs
Work on Process::Trio
Support Merging MergedReports

This commit also moves the Result class into Component::Report
Various hacks to get StatsSummarys to go