MB-10057: implemented basic get_local_vbuuid/2 for 3.0

Not that it's not kind of checkpointing we ultimately want in 3.0. But
in order to merge 2.5.1 stuff it's best to start simple.

This implementation is taking vbucket uuid from failover id using stat
request. And notably, unlike 2.5.1 it will not tolerate crashes due to
3.0's failover id change on unclean shutdown.

Change-Id: I4e63041bcd84c70a1732d20109e69900e2814a2e
Reviewed-on: http://review.couchbase.org/34455
Reviewed-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>
Tested-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>