storage_proxy: Pass token_metadata in some static helpers
storage_proxy: Pass token_metadata in some static helpers

Soon there will be token_metadata on storage_proxy, so
prepare for that in advance.

Signed-off-by: Pavel Emelyanov <c9a32589e048e044184536f7ac71ef92fe82df3e@scylladb.com>

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