Add NonNull annotations to test cases for testing annotation copying

[burdoto]

Closes #3318

This PR introduces @NonNull annotations as part of @Data and @Value classes' fields in order to be copied from fields to constructors, getters and setters as requested in #3318 (comment).

[burdoto]

After writing and testing the modified Test case, I noticed that this does in fact function with the @lombok.NonNull annotation.
The reported issue applies to external annotations such as org.intellij.lang.annotations.Language (as reported in #3318 (comment)) that are affected. However, for the test case, as a new contributor, I dont have enough project insight to correctly introduce external annotations to this test case (let alone since maven fails to import the whole project).