Refund webhook delay

[snekbaev]

Hi,

a couple of month ago I suggested this to the support via email. Opening an issue so it's easier to track.

Payment has a delay for webhooks, refund doesn't. Documentation states one should consider implementing async refunds, okay, did that. Now webhook URL is being invoked in the middle of the refund processing routine. Logic there does checks and replies with the failure, so webhook is retried and within that timespan my routine completes, thus when webhook is invoked again it can be processed. I should be able to specify the delay.

Thank you!