[#501] Add equals and hashCode implementations to PSI class wrappers

[vsantele]

Description of changes made

Implemented equals and hashCode methods in JavaPsiClassWrapper and KotlinPsiClassWrapper to ensure proper comparison and hashing based on the qualified name.

Why is merge request needed

When the PromptManager gets interestingPsiClasses (here) using psiHelper.getInterestingPsiClassesWithQualifiedNames, PsiMethodWrapper.getInterestingPsiClassesWithQualifiedNames is called.
The JavaPsiMethodWrapper and KotlinPsiMethodWrapper create a new instance of the corresponding PsiClassWrapper for each interesting PSI class.

If the same class is added to the MutableSet, two items will be present because they will be two distinct instances of the PsiClassWrapper.

Other notes

Fixes #501
I can't think of any particular case where two distinct classes can have the same qualified name.

Potential improvements

Based on data of a TGA-Pipeline run with the current version of TestSpark, duplicate class signatures has been removed from the prompt, resulting in a potentially significant improvement in performance.

What is missing?

Please mention if anything is missing for this merge request, e.g you have decided to move something to the next merge request

• I have checked that I am merging into correct branch

[github-actions]

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[Copilot]

Pull Request Overview

This PR implements proper equals and hashCode methods in PSI class wrappers to fix duplicate entries in sets when collecting interesting classes for prompt generation. The fix ensures that classes are compared and hashed based on their qualified names rather than object identity.

• Added equals and hashCode implementations to both Java and Kotlin PSI class wrappers
• Both implementations use qualifiedName as the basis for equality and hashing
• Includes validation that qualifiedName is not empty to ensure meaningful comparisons

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 2 comments.

File	Description
KotlinPsiClassWrapper.kt	Added equals and hashCode methods using qualified name comparison
JavaPsiClassWrapper.kt	Added equals and hashCode methods using qualified name comparison

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