Device Attestation Failure

The sample app currently only successfully attests Matter "test" devices. When a "non-test" Matter device is commissioned, the device attestation step fails. However, since PR #92, device attestation failures are simply ignored. Note that this fact is reported as a warning in the "New device information" screen.

We have a couple TODOs on that topic:

• Have a setting to control that behavior
• Support specifying the Root CA to be used (See Issue #90)

Note: Ideally, a dialog would be shown to ask the user whether the device certification failure should be ignored. Unfortunately, this is not possible because GPS controls the screen when we would want that dialog to be shown.