fix: return value of asyncNext should use netty future

[ZhongChaoqiang]

No description provided.

[foreverneverer]

Thanks for your contribution @ZhongChaoqiang .

Change api usually cause compatibility problem and we haven't find the futurebug, so I want to know why you need use netty future, do you meet some bug or some other problem? you can add some description to explain it.

[neverchanje]

Agree with Shuo Jia. It's not trivial to introduce API change. You can describe your requirement and I think we can find out some way that can work around incompatibility.

[ZhongChaoqiang]

@shuo-jia @neverchanje
I don't know whether the original design is to return to the future of jdk. I thought this was a mistake.
If we change to netty future, the code on the application side is not affected because netty future inherits the future of the JDK. In addition, listener can be added without forcible conversion, which is convenient to use.
All other aync APIs use netty future，It's also about uniform usage.

[foreverneverer]

@ZhongChaoqiang good, it's right, I have approved

[levy5307]

@ZhongChaoqiang Thanks for your contribution. Maybe you should add a commit to make the check of semantic succeed. Thanks!