fix(client): Replaced cookie checks with localStorage checks

I tried to change as little as possible to accomplish our goal of relying on `localStorage` checks to determine if we should show the "cookies disabled" page. I consider this a very temporary (and gross) fix. I will happily do something more involved if we'd rather use something like this method going forward.

@ckarlof and @zaach let me know what you guys think. I'm totally open to suggestions here.