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
Oh, sorry, maybe I misunderstood your idea on `ng-alias`, I thought that the idea was that if you have `ng-alias='foo as bar'`, then if you modify `foo`, then `bar` would reflect that change and **viceversa** (of course, everything with `$parse` and expressions). Now, when on top of this you add one-time binding, this is when things get non-trivial. I am not saying impossible, just that need to be done with a lot of care