In this commit, we introduce unit tests for the `MutatingAdmission`
webhook that mutates the `ResourceBinding` resource. These tests ensure
correct behavior for various mutation scenarios and improve coverage:
- Testing the handling of decode errors and ensuring that admission
is denied when decoding fails.
- Full coverage testing of policy mutation, including setting default
UUID labels for the `ResourceBinding`.
- Verifying that only the expected patch for the UUID label is applied,
ensuring no other unnecessary mutations.
Signed-off-by: Mohamed Awnallah <mohamedmohey2352@gmail.com>