fix(codemods/react/19/remove-legacy-context): improve and fix issues in remove-legacy-context codemod

[amirabbas-gh]

📚 Description

This PR fixes multiple issues related to the remove-legacy-context codemod in the react/19 directory. The following changes were made:

1. Fix the main codemod logic: Resolved functional issues in the remove-legacy-context codemod to ensure accurate transformation.

2. Fix test fixtures: Corrected and updated test fixtures to align with the codemod's expected behavior.

3. Handle null cases in findPatterns: Fixed a bug where findPatterns could return null, causing runtime errors during execution.

4. Correct package address: Updated the @codemod.com/codemod-utils package address to the correct location in remove-legacy-context.

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🧪 Test Plan

1. Run tests for the remove-legacy-context codemod:

   npm test

2. Validate the updated fixtures to confirm accurate test results.
3. Ensure no runtime errors occur in scenarios where findPatterns previously returned null.
4. Verify the updated @codemod.com/codemod-utils package address works as intended.

[mohebifar]

This is not used and should be removed