Build a RealmListViewDataSource

[alazier]

Right now users need to copy data when using the built in ListViewDataSource which is not performant. We should be taking advantage of Realm's lazy load architecture by better integrating with this component. If possible we should do this in a general way so that we can achieve the same benefits with other components as well.

[alazier]

I think we should start working on this sooner rather than later - so far we have had two beta users asking about better integration with components. Also see #140

[appden]

This pretty much duplicates #25

[corbt]

This would be really helpful for our app. The only way I've found to update a ListView backed by realm-js is by doing a deep copy of the data on each re-render, which obviously isn't ideal from a performance standpoint. Perhaps just as importantly, the developer experience would also be nicer if I didn't have to worry about this -- currently it takes a lot of thought to make sure I'm covering all the edge cases of places where data could go stale in the realm-to-Listview mapping. It would free up a lot of brain cycles to just be able to declaratively connect those components up and not worry about invalidation logic. :)

I suspect the same issue will come up in other pages in our app where we want to hook realm result objects up to different displays and expect them to update automatically, but we haven't built that out so far so I can't give any explicit feedback. :)