Add functionality to generate "most recent value" for features

How do we include features generated by "most recent value" that could be integrated in collate so that we can define them in the config file?

ACDHS project has a script outside of Triage that generates those features; we should think of a way on how to integrate these valuable features.

Start by reviewing how collate features are defined in the config file and how the ACDHS project’s external script generates “most recent value” features. Determine the integration boundary and document what configuration and generated output are required for the feature to be considered complete.

Written by the indexing model from the issue text.