Introducing new functions in Data.Functor.Utils

(<<$>>) :: Functor f => (a -> b -> c) -> (a -> f b) -> a -> f c
(<<$$>>) :: Functor f => (a -> f b) -> (a -> b -> c) -> a -> f c
iso :: Functor f => (c -> d) -> (a -> b) -> (b -> f c) -> a -> f d
lens :: Functor f => (r -> (a, a -> r)) -> (a -> f a) -> r -> f r