List operations and prefetching were not handling static columns
correctly. One issue was that prefetching was attaching static column
data to row data using ids which might overlap with clustered columns.
Another problem was that list operations were always constructing
clustering key even if they worked on a static column. For static
columns the key would be always empty and lookup would fail.
The effect was that list operations which depend on curent state had
no effect. Similar problem could be observed on C* 2.1.9, but not on 2.2.3.
Fixes#903.
(cherry picked from commit 383296c05b)
988d6cd153