refmt: keep new line characters when using infix operators

It is often more readable to have line breaks when using infix operators.

example 1

thing |> doFirstThing |> doSecondThing |> doThirdThing  |> doFourthThing;

// vs

thing
|> doFirstThing
|> doSecondThing
|> doThirdThing
|> doFourthThing;

example 2:

thing >>= doFirstThing >>= doSecondThing >>= doThirdThing >>= doFourthThing;

// vs

thing
>>= doFirstThing
>>= doSecondThing
>>= doThirdThing
>>= doFourthThing;

refmt currently forces you into the first example when there are less than 80 characters on the line. I'd like to allow both styles.

Start with refmt's formatting logic for infix operators and locate the existing formatter tests. Compare the two styles shown in the issue, then verify that line breaks can be preserved while the current compact style remains supported.