cql-pytest: tests for fromJson() failing to set tuple elements to null
cql-pytest: tests for fromJson() failing to set tuple elements to null

This patch adds a test for trying to set a tuple element to null with
fromJson(), which works on Cassandra but fails on Scylla. So the test
xfails on Scylla. Reproduces issue #7954.

Refs #7954.

Signed-off-by: Nadav Har'El <625169824b719df98706d88646d0aae6f368ae4d@scylladb.com>
Message-Id: <20210124082311.126300-1-625169824b719df98706d88646d0aae6f368ae4d@scylladb.com>

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