Mobile/desktop redirection

- Add mobile/desktop redirection
- Add `gaMobileService` to know in which environment the app is
- Use this service in `ContextPopup` to make the popup usable on mobile

! Prod mode doesn’t work due to unpublicy of `map.getPixelFromCoordinate` !

Yes, there a duplication of mobile detection between `index.mako.html` and `MobileService.js`, but I didn’t want the app to be loaded before redirecting.