Rename key -> pageKey

[clayellis]

In order to increase clarity and consistency, I propose changing the parameter label key to pageKey in the paginate methods.

Motivation

The Swift API Design Guidelines urges us to "Include all the words needed to avoid ambiguity". By changing key to pageKey we remove any ambiguity about what key is — specifically that it is the page key in the query.

This also increases consistency throughout the code since everywhere else (see: Pagination.defaultPageKey) this key is referred to as the pageKey.

Breaking Change?

Potentially, but not drastic. Since the parameter is provided a default value, unless a user has specified the key parameter, there won't be any breaking changes. If, however, they have specified key the compiler can automatically suggest the renamed parameter label which makes upgrading trivial.

[clayellis]

We had talked on Discord about potentially changing instances of pageSize to match the new perPage wording. How do you feel about moving forward on that? Or is it unnecessary.

[anthonycastelli]

Yeah, I say change the pageSize to better match the style we are after here. Definitely makes more sense to keep everything matching and organized that pertains to each other.

[vkill]

+1

The page and per like the kaminari

[anthonycastelli]

I've gone ahead and merged this. 👍

[clayellis]

Awesome, I'll open another PR with the other wording changes.

[anthonycastelli]

Swiftlint was being a pain in the ass so had to fix all of that. But sounds good.