Simplify text labels in XML

[vkbo]

Summary:

Since XML doesn't handle multiple spaces in text in a predictable manner, the item labels should use the new simplified function on all text labels. The same should apply to other user-defined strings in the project.

Related Issue(s):

Reviewer's Checklist:

• The header of all files contain a reference to the repository license
• The overall test coverage is increased or remains the same as before
• All tests are passing
• All flake8 checks are passing and the style guide is followed
• Documentation (as docstrings) is complete and understandable
• Only files that have been actively changed are committed