Add VueRouter to pipeline tabs

With the new Vue pipeline tabs, we were using query params instead of routes to redirect the user to the right tab content. It was working fine, but it did made sharing urls (or refreshing) problematic as you would lose where you were. On top of that, users are accustomed to seeing the route change on changing tab in that section.

This MR introduce VueRouter on each of the existing route and we render the right component based on the route. It also removes all of the query param logic and the redirects inside the rails controller, which is a good riddance 😄