In this commit, we introduce unit tests for the `MutatingAdmission`
webhook that mutates the `ClusterResourceBinding` 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 `ClusterResourceBinding`.
- 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>