secondary index: expand test of secondary-index and UPDATE requests
secondary index: expand test of secondary-index and UPDATE requests

The existing unit test test_secondary_index_contains_virtual_columns
reproduced a bug (issue #4144) with indexing of primary-key columns,
but we only actually tested clustering columns. In issue #4471 there
was a question whether we may still have a bug when indexing of
*partition-key* columns. This patch adds a test that verifies that
we don't, and this case works well too.

Refs #4144
Refs #4471

Signed-off-by: Nadav Har'El <625169824b719df98706d88646d0aae6f368ae4d@scylladb.com>
Message-Id: <20190501113500.25900-1-625169824b719df98706d88646d0aae6f368ae4d@scylladb.com>

scylladb/scylla,avikivity/scylla,avikivity/scylla,scylladb/scylla,scylladb/scylla,scylladb/scylla,avikivity/scylla