Enhancement: there need to be some comment to explain PodOpsLifecycle procedure

[wu8685]

What would you like to be added?

add some comment to explain PodOpsLifecycle procedure in webhook codes, like here https://github.com/KusionStack/kafed/blob/main/pkg/webhook/server/generic/pod/opslifecycle/webhook.go#L123

also the codes here could be refactored more readable.

Why is this needed?

Users may be confused while reading these codes.