When I run `scantxoutset` via RPC using big range (e.g. 10000) on XPUB, the progress report indicator (`scantxoutset status`) reports 100% at start (while the keys are being derived). This is most probably the result of the previous operation. The progress is only reset to zero when the actual scan starts. I would expect the progress is set to zero before the keys are being derived.

Output of periodic calls to `scantxoutset status` while performing long operation.

```
{ progress: 100 }
{ progress: 100 }
{ progress: 100 }
{ progress: 100 }
{ progress: 100 }
{ progress: 100 }
{ progress: 100 }
{ progress: 100 }
{ progress: 100 }
{ progress: 0 }
{ progress: 3 }
{ progress: 6 }
{ progress: 9 }
{ progress: 12 }
{ progress: 15 }
{ progress: 17 }
{ progress: 20 }
{ progress: 23 }
{ progress: 26 }
{ progress: 29 }
{ progress: 32 }
{ progress: 35 }
{ progress: 37 }
{ progress: 40 }
{ progress: 43 }
{ progress: 46 }
{ progress: 49 }
{ progress: 51 }
{ progress: 54 }
{ progress: 57 }
{ progress: 60 }
{ progress: 63 }
{ progress: 66 }
{ progress: 68 }
{ progress: 71 }
{ progress: 74 }
{ progress: 77 }
{ progress: 80 }
{ progress: 82 }
{ progress: 85 }
{ progress: 88 }
{ progress: 91 }
{ progress: 94 }
{ progress: 97 }
{ progress: 100 }
```
{RPCResult::Type::OBJ, "transactionid", "", MempoolEntryDescription()},
                        }},
                    RPCResult{"for verbose = false and mempool_sequence = true",
                        RPCResult::Type::OBJ, "", "",
                        {
                            {RPCResult::Type::ARR, "txids", "",
                            {
                                {RPCResult::Type::STR_HEX, "", "The transaction id"},
                            }},
                            {RPCResult::Type::NUM, "mempool_sequence", "The mempool sequence value."},
                        }},
                },
                RPCExamples{
                    HelpExampleCli("getrawmempool", "true")
            + HelpExampleRpc("getrawmempool", "true")
                },
        [&](const RPCHelpMan& self, const JSONRPCRequest& request) -> UniValue
{
    bool fVerbose = false;
    if (!request.params[0].isNull())
        fVerbose = request.params[0].get_bool();
    bool include_mempool_sequence = false;
    if (!request.params[1].isNull()) {
        include_mempool_sequence = request.params[1].get_bool();
    }
    return MempoolToJSON(EnsureAnyMemPool(request.context), fVerbose, include_mempool_sequence);
},
    };
}
static RPCHelpMan getmempoolancestors()