Support Full-scan Aggregations

[Max-Meldrum]

Full-scan Aggregation Example:

SELECT SUM(fare_amount) FROM yellow_tripdata

This query can also be rewritten if and only if the underlying wheel fare_amount index has been built on the full data. Then
the query can be computed directly through a µWheel Landmark Aggregation (Haw::landmark) which is an O(1) operation.

We must maintain the minimum and maximum timestamps of the time_column to support this. These can then be used to check whether a built wheel index can answer a full-scan aggregation.