set-cookie causes the cache to not cache the page. Since we’re not trying to track the user beyond, we don’t want to try resetting the cookie again with the same info
This fixes https://github.com/LLK/scratchr2/issues/3798 by using regex in expressjs patterns, and then also parsing those regex patterns for fastly, such that we can limit the scope of the regex created for a specific view
This also moves all helper methods in `configure-fastly` into a separate utility file, and adds some additional unit tests for those utilities now that they are separated.
