tool linter: check for leaf nodes with unstripped text content

[bernt-matthias]

another one from the microGalaxy hackaton. bio.tools often contain newlines which are removed by our parser, but it would be better if they would not be there at all (I think).

Created problems for instance in the galaxy_tool_metadata_extractor.

Also removes one test (test_xml_comments_are_ignored) which made no sense (to me).

How to test the changes?

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• [x] 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

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[bernt-matthias]

ping @davelopez

[davelopez]

Also removes one test (test_xml_comments_are_ignored) which made no sense (to me).

I see your point. I cannot remember right now why I added this test. From the #14845 PR description, it sounded like the position (line and character offsets in the text document) of the issues reported by the linter will not match the real document if we have XML comments or additional spaces on it because they get removed by the parser before linting. But it looks like this will not prevent the parser from removing them anyway.

[github-actions[bot]]

This PR was merged without a "kind/" label, please correct.