`Result.Err` recovering

[lue-bird]

Currently there's only

Result.withDefault :
    a -> Result x a -> a

which the issue suggests to replace with

• Result.valueElseOnError/recover :
      (x -> a) -> Result x a -> a

  which is lazy by default and makes it nearly impossible to forget error values.

• additionally, an andThen but for the error case would be a common helpful operation

  Result.onErrorTry/recoverTry :
      (x -> Result a y) -> Result x a -> Result y a