[wasm] spread WS based timers over next 6 minutes to prevent heavy throttling

[pavelsavara]

Problem

Chromium browsers throttle setTimeout frequency on inactive pages to 1 sec almost immediately.
5 minutes later they throttle heavily to wakeup each 60 seconds.
That breaks dotnet Timer expectations and also threadpool.

The heavy throttling could be lifted back to 1sec if there was WebSocket activity.
https://developer.chrome.com/blog/timer-throttling-in-chrome-88/#intensive-throttling

Implementation

The idea is to cover the future 6 minutes with "wakeup" timer, each 1 second apart from each other.
1 second, because is the light throttling rate, so it would not help to try to do it more often.
It should be triggered from WS event, so that it's only 1 deep from it.
Every subsequent call would schedule only for uncovered future.

There is [OuterLoop] unit test for this.

Fixes #51041