fix: catch the `$viewContentLoaded` earlier

When the breadcrumb uses an external template, the linking of the directive
is paused during the template file's loading. If the current state is
configured with an inline template, the view is loaded faster than the
breadcrumb's directive. The directive misses The `$viewContentLoaded` and
the breadcrumb is empty. Solution : Listen the event in the service, very
early in the lifecycle.

Closes #14