Feature request:Add Sink/Flow.forall operator

[He-Pin]

Motivation:
Add Sink.forall which can be implemented with fold / statefulMap, just act as Nil.forall)

Both zio and fs2 has this method.

Result:
rich operators set, and It works as Java Stream 's allMatch.

[He-Pin]

@laglangyue Would you like to take care of this, thanks.

[pjfanning]

@laglangyue could you consider filling in an Apache committee form? For larger PRs, we require this. See the CONTRIBUTING.md page on this repo - basically this: https://www.apache.org/licenses/contributor-agreements.html

[laglangyue]

Would you like to take care of this, thanks.

willing to do this

could you consider filling in an Apache committee form?

yeah，i will complete it as soon as possible

[laglangyue]

could you consider filling in an Apache committee form?

I had sended it to [email protected]. it's my form