Fix links to @ParameterizedTest support classes in the user guide

[eliasnogueira]

Overview

This PR fixes broken links in the user guide as referred to in #3673

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Definition of Done

• There are no TODOs left in the code
• Method preconditions are checked and documented in the method's Javadoc
• Coding conventions (e.g. for logging) have been followed
• Change is covered by automated tests including corner cases, errors, and exception handling
• Public API has Javadoc and @API annotations
• Change is documented in the User Guide and Release Notes

[marcphilipp]

Thanks! We should look into validating these links at some point to prevent this from happening in the future.