refactor(ip): rename identifiers to match other casing

[wooorm-arcjet]

When working on the fastify integration, i used @arcjet/ip.

I noticed that I needed the Cidr type, which is a return value of parseProxy from there.
So I expose it here.

I also noticed that there are 2 functions, parseProxy as a named export and findIp as the default export.
I expose the latter as a named export too, and deprecate the default symbol.

Internally, the casing of abbreviations was more capital heavy, and not always consistent (parseCIDR and isIPv4Cidr). Especially around symbols such as isIPv4Cidr (previous casing), I find it hard to come up with good arguments why that P is uppercase but v lowercase.
I like using capitals only for word boundaries: parseCidr, isIpv4Cidr, Cidr.
So, before exposing values, I changed their internal names. See GH-4478 for more on that.

[trunk-io]

😎 Merged successfully - details.

[blaine-arcjet]

IPv4 and IPv6 are specific terms: https://en.wikipedia.org/wiki/IPv4, https://en.wikipedia.org/wiki/IPv6
CIDR is abbreviated as all caps: https://en.wikipedia.org/wiki/Classless_Inter-Domain_Routing

Stylistic changes like this grow the scope of a PR and make it harder to review the functional changes. We should keep PRs focused on the task outlined in the semantic commit. I suspect these crept in due to the desire to name the external API findIp instead of findIP, the bikeshedding of which is why I exported it as a default when I wrote the library.

[wooorm-arcjet]

Internally different cases are already used, see my OP: parseCIDR, isIPv4Cidr.
GitHub and npm are also specific terms and in normal usage cased a certain way, but, that casing I believe should not be used in camelcased symbol names. More on that in OP and in GH-4478.

Another way how I think of it: come up with a lower dash case name, and then turn -[a-z] into caps. So, parse-cidr, is-ipv4-cidr, from-github, to-npm -> parseCidr, isIpv4Cidr, fromGithub, toNpm.

As for 2 PRs, if you want that I will do that but I didn’t because that’s what GH-4478 is about.
In the mean time I split the commits and marked them as being about renaming internals or about exposing values

[arcjet-rei]

My primary objection to these kinds of stylistic changes is that once you start making them, there's no end to it. My own preference, which is informed by spending a bunch of time immersed in American style guides (which tend to differ from both UK and European style guides), is that all acronyms are always upper-cased, and v for version is lowercased, as it's a sigil more than a letter in that use case. That said, I would rather live with some inconsistency than clutter git blame with purely stylistic changes.

Exporting findIP as a named export is a good idea and LGTM. I would also like to get this PR merged. My preference and recommendation would be to drop the stylistic changes for now and get that piece landed.

[wooorm-arcjet]

I split this work. This PR is now only refactoring. I’ll export the type, and the named export, in follow up PRs!