[Feat] Enable route guards

[meeroslav]

Route unregister should be called upon route destroy. Unregistering route will remove it from the routes$ and trigger navigation. This is precondition to having route guards using structural directives.

The intended behaviour is different to @angular/router canActivate:

Guard	true	false
@angular/router	navigate to route	stop navigation
angular-routing	navigate to route	navigate to fallback route