[iOS]getAll and clearAll never resolve/reject on iOS 11.2.x

[tyleralves]

OS: iOS Device: iPhone 7 Plus Version: 11.2.x Library Version: 3.3.0 (npm latest)

getAll and clearAll usually hang and never resolve/ reject. This is because of a bug in iOS 11.2.x where the callbacks for HttpCookieStore native methods are never called.

It is a well reported bug on stackoverflow: https://stackoverflow.com/questions/49452968/wkhttpcookiestore-setcookie-completion-handler-not-called https://stackoverflow.com/questions/54246400/wkhttpcookiestore-getallcookies-doesnt-always-call-completionhandler/54261605

[tyleralves]

#150 fixes the bug in clearAll by avoiding WKHttpCookieStore::getAllCookies

[safaiyeh]

I have forked the repo here: https://github.com/safaiyeh/react-native-cookie-store We can create issues and PRs there to continue the development of the project.