Can we add tests for cloudtrail.utils with Improved Mocking and Edge Case Handling

[imSanko]

Describe the issue

Replaced manual mocking with the @mock.patch decorator for more explicit and isolated testing.
Added new tests to cover edge cases:

1. Handling of empty responses from get_caller_identity.
2. Invalid ARNs passed to get_account_id_from_arn.
3. Missing trails in the response of describe_trails.
4. Verified error handling by testing for expected exceptions (KeyError and ValueError) in scenarios with malformed inputs or empty responses.

Additional Information/Context

No response

CLI version used

Last Update

Environment details (OS name and version, etc.)

UNIX