feat: adding support for cookie auth

[erunion]

🧰 What's being changed?

This adds support for being able to handle cookie auth throughout our general Explorer authentication flows.

It functions identical to how apiKey works, just that if in is set to cookie, the payload will be sent as a cookie.

Resolves https://github.com/readmeio/api-explorer/issues/89

🧪 Testing

I've added an addition to our auth-types example and support can be seen there:

For comparison this is what it looks like against master:

[erunion]

:easy:

[erunion]

api doesn't support this yet, but will with readmeio/api#38.

[domharrington]

Resolves a 2 year old issue:

😍

I guess a next step would be adding support from reading from document.cookie as well? Then there's the whole Link spec stuff...

[erunion]

Really not sure if I want to ever support reading from document.cookie when we have JWT readily available. But yeah Link stuff. 😬

We should have a larger discussion about that some point.

[domharrington]

I think if we had Link support we'd never need to read from document.cookie right?

[erunion]

Kind of, but a (the?) problem with the Link spec right now is that it has no formal support for auth flows so there isn't quite a spec-friendly way to grab data from a response and re-use it in auth.