[Feature]: add waitAsync method

[zhongkechen]

What would you like?

I would like to have waitAsync

var future = context.waitAsync(Duration.ofSeconds(5)); // non-blocking
future.get();  // wait for 5 seconds

So that the wait future

• can be used with other futures in anyOf
• limit the total time since the wait future created

Possible Implementation

No response

Is this a breaking change?

No

Does this require an RFC?

No

Additional Context

No response