This commit pushes down quals or order_by columns to make
use of the SegmentMetaMinMax objects. Namely =,<,<=,>,>= quals
can now be pushed down.
We also remove filters from decompress node for quals that
have been pushed down and don't need a recheck.
This commit also changes tests to add more segment by and
order-by columns.
Finally, we rename segment meta accessor functions to be smaller
2bf97e452d