Adapt the pagination branch and resolve the layer violation

This branch builds on !76 (closed) by @abompard to implement the wrapper I was thinking about and resolve the existing layer violation in SubscriptionService. Rather than try to explain what I was thinking (or more accurately, to figure out exactly what I was thinking ), I just experimented until I came up with something that seems acceptable.

@abompard please let me know if this is acceptable for your purposes. If so, I'll land this instead of !76 (closed) and we'll use it to close #172 (closed) and #180 (closed)