Converters: add missing tests and add linting to converter tests

[bernt-matthias]

While working on #12073 I realized that tests of many converters use the wrong attribute format instead of ftype and that tests are missing for many converters.

The PR

• adds planemo lint to the converter tests
• adds tests to almost all converters (a few are excluded via a new skiplist)

This replaces #12104 (in parts).

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 contributions under Galaxy's current license.
• I agree to allow the Galaxy committers to license these and all my past contributions to the core galaxy codebase under the MIT license. If this condition is an issue, uncheck and just let us know why with an e-mail to [email protected].

[bernt-matthias]

Heureka. Tests are passing. Good to go from my side.

[jmchilton]

Amazing - thank you so much!

[github-actions]

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