Add clientcert expiration date as core fact.

Use Case

Would be nice to see when clientcerts expire so we know when they need to be rotated, especially when using an external cert provider.

Describe the Solution You Would Like

Add expiration_date to the trusted fact hash

Describe Alternatives You've Considered

Build custom facts, however, the cert name is not available during the custom fact generation in order to get the cert file.

Additional Context

Add any other context or screenshots about the feature request here.