RFC Compliant Cookie Parsing

[t-ae]

⚠️ Vapor now has stricter cookie parsing. If you're relying on non-standard cookie parsing (like non-ascii characters) you'lll need to migrate off before updating ⚠️

Changes cookie name parsing to conform to RFC6265 and RFC2616.

• Some characters (!"#$%&'*+^`) are newly allowed
• Non-ASCII characters are banned

#2540

[t-ae]

This PR contains the improvements I suggested in #2511.

I also renamed isDirectiveKey to isTokenCharacter to clarify the definition is from RFC.

I afraid that banning non-ASCII characters can cause problem.
isTokenCharacter is used in parseDirectives, and parseDirectives is also used for other headers.
As far as I can see, none of them allows non-ASCII character as directive key. Can anyone verify it?

Here's the list of headers which use parseDirectives:

• https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Accept
• https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Content-Type
• https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Cookie
• https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Content-Disposition
• https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Set-Cookie
• https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Forwarded

[0xTim]

Thanks!

[tanner0101]

These changes are now available in 4.41.4