CookieSync: syncs cookies to localhost

This is an add-on which copies cookies to localhost. This addon monitors all incoming cookies and all cookies matching a user defined name regex will be copied to the http://localhost domain. It's primary here for developers that have code running on their localhost which connects to other services and need access to their cookies. The typical use case is a third-party login flow. In production the developer's code wil run on the same domain as the other services and have access to the cookies they set. But when code is running on localhost (during development), those cookies are not accessible in the browser. This add on makes those cookies available on localhost, so available to the developer's local code.