Collection History

This PR adds `lastUsed` to a collection.

On updates to a collection in live, it pushes the `id` to the head of `lastUsed`.
On updates to draft, it updates `lastUsed` upon publishing only; It will be the difference between `draft` and `live`.

@stephanfowler `previously`? `history`?
Type inference just didn't happen to some people, did it?! :wink: