Function bicoro::map_output

pub fn map_output<'a, Input, OutputA, OutputB, Result, MapFn>(
    co: Coroutine<'a, Input, OutputA, Result>,
    map_fn: MapFn
) -> Coroutine<'a, Input, OutputB, Result>where
    MapFn: Fn(OutputA) -> OutputB + Send + 'a,
    OutputA: Send,
    Result: Send,

Takes a coutine outputting A, and makes it output B

This is a specialization of intercept_output, when we don’t need to have any affects