decouple klog and event recorder from the main flow

[sanposhiho]

scheduler_perf shows the latency drop when the guests use logs and event recording.
Currently, we send logs and events from guests to hosts synchronously, but actually we can accept the delay in logging and event recording actually.

Probably we just keep logs and events in the guest's side when klog / event recorder is used and ship them to the host once the main function finishes. (goroutine isn't an option, wasm doesn't support it)

/kind feature