Add webhook framework

[kerthcet]

Pull Request Description

[Please provide a clear and concise description of your changes here]

Related Issues

xref: #710
copy of #713

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[kerthcet]

wait a minute, seems I didn't revert back the manifest cmd.

[kerthcet]

Finished, PTAL @Jeffwan

[Jeffwan]

The change looks good to me. I've reviewed it in earlier closed PR. Great and we have webhook now!