materialized views: match base and view replicas
materialized views: match base and view replicas

A function to find the appropriate replica to send a view update to.

This patch creates a new source file db/view/view.cc. We should
eventually move a lot more of the materialized views code there.

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

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