Fix ReplaceLambdaWithMethodReference to not replace lambdas inside anonymous inner classes

[timtebeek]

Summary

• Fixed ReplaceLambdaWithMethodReference recipe to not replace lambdas inside anonymous inner classes
• Added logic to detect when we're inside an anonymous inner class and prevent transformation
• Added comprehensive tests to verify the fix works correctly

Background

The ReplaceLambdaWithMethodReference recipe was incorrectly replacing lambdas with method references inside anonymous inner classes. This could change the semantics of this references, as demonstrated in issue #722.

For example, this transformation was happening incorrectly:

B b = new B() {
    @Override
    public void run() {
        new Thread(() -> run()).start(); // This should NOT become this::run
    }
};

The lambda () -> run() calls the anonymous inner class's run() method, but this::run would refer to the outer class's context.

Changes Made

1. ReplaceLambdaWithMethodReference.java: Added logic to traverse up the cursor tree to detect if we're inside an anonymous inner class (J.NewClass with a body)
2. ReplaceLambdaWithMethodReferenceTest.java: Added three comprehensive test cases:
   • doNotReplaceInAnonymousInnerClass() - Basic case with recursive call
   • doNotReplaceInAnonymousInnerClassWithOtherMethods() - More complex case with multiple methods
   • stillReplaceInRegularInnerClass() - Ensures regular inner classes still work correctly

Test plan

• Added test cases covering the fix
• Verified existing tests still pass
• Tested that regular inner classes still get lambda-to-method-reference transformation
• Verified anonymous inner classes no longer get incorrect transformations

Fixes #722

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