Range deletions of specific columns are not well-defined (range tombstones cover entire rows) and are forbidden in Cassandra, so we follow suit. This commit comes with a simple test. Fixes #5728 Tests: unit(dev) Message-Id: <896264f5f5790b9f96fcc18655ac3248a6abf37a.1583424131.git.sarna@scylladb.com>