Make use of ìnto_future` for requests and messages

[caspervonb]

• Makes Client::publish return an into_future based builder
• Makes Client::request return an into_future based builder.
• Makes Context::request return an into_future based builder.
• Makes Context::publish return an into_future based builder.

[Jarema]

1. Fix the conflicts
2. As this is close to 1.0 changes, maybe we can have kv hotpath operations here too?

[paolobarbolini]

Having the IntoFuture implementations return BoxFutures looks very inefficient

[caspervonb]

Having the IntoFuture implementations return BoxFutures looks very inefficient

Aye, inferring the type without boxing will help here. But it's still nightly.

[paolobarbolini]

Having the IntoFuture implementations return BoxFutures looks very inefficient

Aye, inferring the type without boxing will help here. But it's still nightly.

If they come out when you're in 1.0 though you'll have to make a breaking release. I could look into manually implementing the Future for it.

[paolobarbolini]

Does this need to be public?

[caspervonb]

It does not.

[Jarema]

@caspervonb I would put it in queue for final review and merge after concrete errors for JetStream are merged, so we have only one conflict solving step.

[caspervonb]

Quite a few conflicts in this one, closing in favor of #1003