feat(key): add Equal method to compare key bindings

[Kapparina]

• Implement Equal method to check for equality of keys and help text.
• Import slices package to simplify key comparison logic.

Summary

This Pull Request introduces a new method to compare Binding objects for equality and updates the imports in the key.go file to include a new dependency.

Main Changes

1. Added a new Equal method for the Binding struct to compare equality by checking keys and help values.
2. Updated imports to include the slices package to assist with operations like sorting and comparing slices.
3. No changes were made to existing logic besides the addition of the Equal method.