Add blocking_recv method to oneshot::Receiver

[gretchenfrage]

Is your feature request related to a problem? Please describe.

I would like to be able to send a value into a oneshot, and receive it either in an async context or a blocking context, to create an API which supports in both blocking and async contexts.

Describe the solution you'd like

mpsc::Receiver and mpsc::UnboundedReceiver have blocking_recv methods. It would be nice to see an equivalent blocking_recv method added to oneshot::Receiver.

Describe alternatives you've considered

It would be interesting to instead simply expose the crate::future::block_on mechanism by which the existing blocking_recv methods are implemented, and have a concept of "this async function doesn't aaactually rely on tokio and thus can be used in a non-async context in a blocking way with that wrapper."

Additional context

It's for the winit-main crate if you're curious.

[Darksonn]

I'm fine with adding this, though note that futures::executor::block_on is a solution that works today.

[Rustin170506]

I am working on this.

[besok]

Apparently the issue should be closed

[Darksonn]

Thanks.