Add bigbed to bed converter and tests

[d-callan]

adding a bigbed to bed datatype converter. see galaxyproject/brc-analytics#371

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.
• Instructions for manual testing are as follows:
  1. [add testing steps and prerequisites here if you didn't write automated tests covering all your changes]

License

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

[d-callan]

does this need anything else from me? im not sure i understand the failures tbh..

[mvdbeek]

Can you take a look at the artefacts in https://github.com/galaxyproject/galaxy/actions/runs/13901245452?pr=19787 ? The first 3 tests are failing. <output name="bed_output" value="output.bed" ftype="bed"/> means that we're expecting an exact match between what the converter generates and the output file that you've included in the PR. You can use any of the assert_contents statements and remove the explicit comparison with output.bed. has_n_lines (https://docs.galaxyproject.org/en/latest/dev/schema.html#has-n-lines) would be enough I think.

[mvdbeek]

Thanks @d-callan!