Before this commit:
To make a controller (@route) trackable, we should add 'track=True' on the
@route.
It would then correctly track the route BUT there were 2 problems:

1. It was not easily (or at all) configurable. It should be hardcoded in routes
   and therefore, the behavior/use case was not the same as website.page which
   use the checkbox on optimize SEO 'Track Page'.
2. Some routes returns an 'ir.ui.view' as main object, some don't (eg: /blog
   return blob.blog while /event return ir.ui.view).
   Problem was, the option to track a page was only displayed if the
   main object was an ir.ui.view or a website.page.
   So even if the checkbox was shown for some routes (thoses returning an
   ir.ui.view as main object), checking or unchecking it would in fact have no
   effect because for @routes it would only check for track=True on the route
   itself.

Now:
1. track=True on @route is gone, we use the route's view's track state like
   website.page does.
2. Since every routes have a template (even if they don't return an ir.ui.view
   as main object), we use it to store the track state of the page.
   This way, the behavior/use case is the same for static or dynamic pages.

This commit depends on community commit setting copy_template & viewid