[24.1] Remove linter for unstripped text content for tool xml leaves

[bernt-matthias]

reverts #17656

we have to many xml nodes where this is allowed (e.g. command) and limiting the linter to a statically defined list of node types seemed difficult to maintain

replaced this with a change in the xsd that should lead to the automatic removal of surplus white spaces (leading/trailing are removed, multiple whitespaces are replaced by a single space) for some of the node types that were the original motivation for the linter (if this proves useful this could be used for more node types).

How to test the changes?

(Select all options that apply)

• [ ] I've included appropriate automated tests.
• [x] 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

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