Use {request, response} format for normalizeFn to get consistency with scrubFn

[twolfson]

Original issue: twolfson/nine-track-original-fork#1

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If someone writes code for scrubFn and wants to move it to be used in normalizeFn or vice versa. It is requires a rewrite to be done. If we use the same signature, then we allow interchange easily.

[twolfson]

When we take this on, be sure to update eight-track-normalize-multipart.

[twolfson]

Another option to preserve backwards compatibility with plugins would be to move to (request, response) for function signature which is consistent with node's http. However, this is less consistent with our saved data.