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
one-time bindings would not make sense for an alias, because it would be completely unrelated to change detection (in my vision of it) --- so a one time binding would not matter, and that's fine