Lazily perform searches by yielding results instead of collecting into an array

[matthewryanscott]

With large product and order sets, out-of-memory situations can occur on memory-constrained systems such as Heroku dynos.

This lets you lazily load search results; additional results are only fetched when the previous batch is exhausted.

[matthewryanscott]

Actually meant to open this in our fork, but I'll leave this open in case your team finds this useful!