test/alternator: add TTL test for more data
test/alternator: add TTL test for more data

The existing TTL tests use only tiny tables, so don't exercise the
expiration-time scanner's use of paging. So in this patch we add
another test with a much larger table (with 40,000 items).

To verify that this test indeed checks paging, I stopped the scanner's
iteration after one page, and saw that this test starts failing (but
the smaller tests all pass).

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

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