Expose `JavaScriptEventLoop.queueMicrotask` and `.setTimeout`

[kateinoigakukun]

This allows users to have more flexibility to customize. For example, this allows inserting operations before/after single job execution loop. e.g. It's useful to enable React batch rendering per job execution loop by ReactDOM.unstable_batchedUpdates.

let original = JavaScriptEventLoop.shared.queueMicrotask
JavaScriptEventLoop.shared.queueMicrotask = (job) => {
  ReactDOM.unstable_batchedUpdates(() => {
    original(job)
  })
}

[github-actions[bot]]

Time Change: -141ms (0%)

Total Time: 18,740ms

Test name	Duration	Change
Serialization/JavaScript function call through Wasm import	23ms	+1ms (5%)	🔍
Serialization/JavaScript function call through Wasm import with int	20ms	-2ms (11%)	👏

View Unchanged

| Test name | Duration | Change | | :--- | :---: | :---: | | Serialization/JavaScript function call from Swift | 200ms | +2ms (0%) | | Serialization/Swift Int to JavaScript with assignment | 448ms | -7ms (1%) | | Serialization/Swift Int to JavaScript with call | 1,384ms | -12ms (0%) | | Serialization/JavaScript Number to Swift Int | 480ms | +3ms (0%) | | Serialization/Swift String to JavaScript with assignment | 508ms | -4ms (0%) | | Serialization/Swift String to JavaScript with call | 1,493ms | -10ms (0%) | | Serialization/JavaScript String to Swift String | 5,976ms | +30ms (0%) | | Object heap/Increment and decrement RC | 8,191ms | -140ms (1%) |

View Baselines

| Test name | Duration | | :--- | :---: | | Serialization/Call JavaScript function directly | 2ms | | Serialization/Assign JavaScript number directly | 3ms | | Serialization/Call with JavaScript number directly | 5ms | | Serialization/Write JavaScript string directly | 4ms | | Serialization/Call with JavaScript string directly | 4ms |