feat(ngRepeat): expose the iterating properties over the alias

Expose the properties `$index`, `$first`, `$middle`, `$last`, `$odd` and `$even` as part of the alias

Closes #9582
we can't break it, but I don't think we should make it terrible either. Either create a new name for the property, or extend the microsyntax (bad), or come up with  something else for this.