CBLIS: Optimize relationship query cache
CBLIS: Optimize relationship query cache

- Not using view prefix for relationship views.
- Call view's -updateIndex and check lastSequenceIndexed if the view index was changed or not. If not changed, return the cached result if it's available.

#960

couchbase/couchbase-lite-ios,amco/couchbase-lite-ios,couchbase/couchbase-lite-ios,amco/couchbase-lite-ios,amco/couchbase-lite-ios,amco/couchbase-lite-ios,amco/couchbase-lite-ios,couchbase/couchbase-lite-ios,amco/couchbase-lite-ios,brendand/couchbase-lite-ios,brendand/couchbase-lite-ios,couchbase/couchbase-lite-ios,brendand/couchbase-lite-ios,couchbase/couchbase-lite-ios,brendand/couchbase-lite-ios,couchbase/couchbase-lite-ios,brendand/couchbase-lite-ios,amco/couchbase-lite-ios