Please describe the feature you'd like to see added.

loadtxoutset should return more quickly, perhaps just checking that the file exists. There should be another RPC to monitor the status.

Is your feature related to a problem, if so please describe it.

1. loadtxoutset takes too long, even requiring -rpctimeout=0. This makes it hard for potential integrations like Umbrel, BTCPay server or Specter desktop to show progress.

2. Progress can only be followed via the debug log, which is too noisy during IBD.

Describe the solution you'd like

It could follow the same pattern as scanblocks, with start, status and abort. The latter two won't need an argument. This would not be backwards compatible, but imo that's fine as long as it lands before mainnet support.

Describe any alternatives you've considered

No response

Please leave any additional context

No response