Add `subscribeToMore` functionality to `useQueryRefHandlers`, `useBackgroundQuery`

[bignimbus]

Context: https://community.apollographql.com/t/how-to-use-subscriptions-together-with-preloadquery/7434/3

Some of our hooks include subscribeToMore in the results object. We want to ensure that all relevant hooks include subscribeToMore, including useQueryRefHandlers and useBackgroundQuery.