eyre: add authentication checker scry endpoint
Lets you check whether a specific Cookie header value string constitutes an
authenticated request.
/ex/=//=/authenticated/cookie/(scot %t 'cookie-string')
Intended for use in the runtime, for example with
%approved ``noun+!>((~(has in approved.cors-registry) u.origin))
%rejected ``noun+!>((~(has in rejected.cors-registry) u.origin))
==
+ ::
+ [%authenticated %cookie @ ~]
+ ?~ cookies=(slaw %t i.t.t.tyl) [~ ~]
+ :^ ~ ~ %noun
+ !> ^- ?
+ %- =< request-is-logged-in:authentication
+ (per-server-event [our eny *duct now scry-gate] server-state.ax)
+ %*(. *request:http header-list ['cookie' u.cookies]~)
==
?. ?=(%$ ren)
[~ ~]
