sstableloader: add consistency-level option
sstableloader: add consistency-level option

Statements can now use configurable consistency level,
which defaults to ONE.
Message-Id: <928b4600d8652ef5ffe254696b78a606ff5684c5@scylladb.com>

scylladb/scylla-tools-java,scylladb/scylla-tools-java,scylladb/scylla-tools-java,scylladb/scylla-tools-java