`view` could be implemented in terms of MonadAsk

Generalizing `view` is nice, as it allows you to use `view` in a `MonadAsk` context like `use` in a `MonadState` context.

```purescript
-- | View the focus of a `Getter`.
view :: forall s t a b m. MonadAsk s m => Getter s t a b -> m a
view l = ask >>= unwrap (l (Forget id))
```

