Bug#16447483: PARTITION PRUNING IS NOT CORRECT FOR RANGE COLUMNS

The problem was in get_partition_id_cols_range_for_endpoint
and cmp_rec_and_tuple_prune, which stepped one partition too long.

Solution was to move a small portion of logic to cmp_rec_and_tuple_prune,
to simplify both get_partition_id_cols_range_for_endpoint and
get_partition_id_cols_list_for_endpoint.