Custodian should emit an RPC notification status event when the recieve process completes sucessfully

[ffranr]

The custodian handles receiving assets. It should emit an RPC notification status event over the subscribers channel which is initialised via the RPC endpoint SubscribeReceiveAssetEventNtfns. This feature was requested by a user on slack here.

Currently, the custodian does emit events emanating from the proof courier. This is an example of an event notification sent to subscribers:

taproot-assets/proof/courier.go

Line 704 in 1e24b99

subscriberEvent(waitEvent)

The new event should implement the fn.Event interface. It should contain (as fields) the corresponding address by which the asset was sent.

The new event should be emitted at this point:

taproot-assets/tapgarden/custodian.go

Line 459 in 1e24b99

}

[dstadulis]

Would like to consider what other event notifications could be added that may be helpful applications to use

[ffranr]

Would like to consider what other event notifications could be added that may be helpful applications to use

@dstadulis A user on Slack requested an event notification which would be published once a sufficient number of confirmation block had been mined. (Confirming an asset transfer.)

[dstadulis]

How about just subscribe to confirmation count or reporting when the tap client meets it's "confirmed" threshold