CLI: pull workflow from GA4GH TRS endpoints

[mlin]

[mlin]

https://github.com/ga4gh/tool-registry-service-schemas https://editor.swagger.io/?url=https://raw.githubusercontent.com/ga4gh/tool-registry-schemas/develop/openapi/ga4gh-tool-discovery.yaml

[dpark01]

Just adding a +1 here.

It's awesome that miniwdl run can accept WDL input from a local file path or a web URI--even resolving relative file path imports properly in the process (e.g. miniwdl run https://raw.githubusercontent.com/broadinstitute/viral-pipelines/master/pipes/WDL/workflows/assemble_refbased.wdl succeeds in pulling its dependencies in).

Being able to do something similar via TRS, specifically: miniwdl run https://dockstore.org/api/api/ga4gh/v2/tools/%23workflow%2Fgithub.com%2Fbroadinstitute%2Fviral-pipelines%2Fassemble_refbased/versions/master/plain-WDL/descriptor//pipes/WDL/workflows/assemble_refbased.wdl would be awesome but currently doesn't work. That URI is what I get when I click on the "TRS" link presented on that particular workflow's Dockstore page. This would make it easier to present a single, definitive source for where folks should find the latest versions of my workflows, regardless of what execution engine they prefer to use.