ReplaceInitMockToOpenMock: Ensure unique name for added tearDown method

[amishra-u]

What's changed?

This pr updates the ReplaceInitMockToOpenMock recipe to avoid creating duplicate tearDown methods. Previously, the recipe would unconditionally add a tearDown method, potentially causing conflicts if one already existed in the class. The new logic checks for existing methods named tearDown and appends the next available numeric suffix (e.g., tearDown0, tearDown1, etc.) to ensure method name uniqueness.

Checklist

• I've added unit tests to cover both positive and negative cases
• I've read and applied the recipe conventions and best practices
• I've used the IntelliJ IDEA auto-formatter on affected files

[github-actions]

Some suggestions could not be made:

• src/main/resources/META-INF/rewrite/examples.yml
  • lines 2583-2598
  • lines 3392-3391
  • lines 3427-3445