Demo application state

[amtins]

As a demo user, I'd like to be able to share the URL where I am with another user, so that the user can run the same test as me.

Acceptance Criteria

• URLs are shareable
• Custom sources URL are shareable
• On the example page :
  • custom source must be available in the URL
  • search page the selected query BU and search query must present in the URL
• On the list page the current level of the navigation must be shareable
• Fix the routing when the demo is deployed on github pages