Optimize treefix operations

[VictorCMiraldo]

It is very common to ues code such as:

... $ utxMap f $ utxLCP p q

which can be fused with a better utxLCPWith:

... $ utxLCPWith f p q

utxLCPWith :: (forall at . UTx phi at -> UTx psi at -> res at)
                   -> UTx phi at -> UTx psi at -> UTx res at

utxLCP = utxLCPWith (:*:)

Another pattern we can optimize is the

... $ foldr f e $ utxGetHolesWith' g p

[VictorCMiraldo]

Another pattern I use a lot:

... $ utxGetHolesWith' f $ utxLCP p q