repair: Add get_full_row_hashes_source_op
repair: Add get_full_row_hashes_source_op

It is a helper that works on the source() of the
get_full_row_hashes rpc stream verb.

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