Apply soft word wrap also to notes when using --pretty

[ilevkivskyi]

We only wrap errors, not notes with --pretty. Notes require special care because they contain function signatures (e.g. for overloads and protocols). It would be great to also nicely fit them to terminal width, for example:

        def [T <: SomeBound] meth(self, one_argument: T, other_argument: T) -> List[T]: ...

may become

        def [T <: SomeBound] meth(self,
                                  one_argument: T,
                                  other_argument: T) -> List[T]: ...

This is a follow-up for #7440