Improved pagination support

[hwillson]

Broken out from #2331. We'll use this issue to track feature work for improving pagination support (which will cover API changes and new helpers).

The goals are to:

• Provide a way to ignore pagination arguments in the cache key
• Provide a way to make bigger records that can link a paginated field to the underlying list
• Provide a way to merge the lists in Records as they come in, making sure the list stays continuous
• Provide a higher level API for relay connection that does all of the above with minimal user effort

[jpvajda]

We'll want to break down this ticket a bit and provide some details before we start working on it.

[BoD]

Marking as resolved for now, as we're now entering a phase of collecting feedback from the community, and so adjustments and more work on this topic is probably upcoming! Will track in new specific tickets.