Implement Declarative Testing for Workflow Behaviors

[jmchilton]

test_workflows.py has long grown unwieldy and many tests are just running workflows and checking outputs. I think these should be broken out and done in a declarative manner. I was also pondering #18541 and trying to think about how and where to describe the expected behavior and I didn't think just adding another test to the monster file was the right approach. I think there are limitations to what is being done with framework test tools (added in 569c5db) but they are better than a bunch of Python test cases I believe. In this PR, I have created a framework for running workflow framework tests to match framework tool tests. I've migrated a few workflow tests to the framework and I have implemented my desired test for #18541.

The syntax is not exactly what Planemo uses for workflow tests... but it is close and I think we can converge there over time. The biggest change is just input descriptions - the workflow tests grew up around automatically generated fixtures and Planemo is optimized for users specifying actual files. So the input specification is different - but they already different in the string-ified YAML throughout the test framework. I've implemented the elements syntax introduced by @mvdbeek for Planemo in galaxyproject/planemo#1417.

How to test the changes?

(Select all options that apply)

• I've included appropriate automated tests.
• This is a refactoring of components with existing test coverage.

License

• I agree to license these and all my past contributions to the core galaxy codebase under the MIT license.

[mvdbeek]

That does look cleaner, thank you!