feat: Add functionality to manifest V2 for comparing against present time. #566
Description
Problem Statement
We have a feature request to compare a given date of birth extracted from a credential against current time and check that the difference is larger than 18 years. Our new predicates can support this, but we don't yet have the ability to compare against "environmental" variables
Goal: Quickly add a comparison against time. The source of the time could be trusted for now, or we could use the date header from the response, or a more sophisticated scheme.