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 }
```
{
    return RPCHelpMan{"savemempool",
                "\nDumps the mempool to disk. It will fail until the previous dump is fully loaded.\n",
                {},
                RPCResult{RPCResult::Type::NONE, "", ""},
                RPCExamples{
                    HelpExampleCli("savemempool", "")
            + HelpExampleRpc("savemempool", "")
                },
        [&](const RPCHelpMan& self, const JSONRPCRequest& request) -> UniValue
{
    const CTxMemPool& mempool = EnsureAnyMemPool(request.context);
    if (!mempool.IsLoaded()) {
        throw JSONRPCError(RPC_MISC_ERROR, "The mempool was not loaded yet");
    }
    if (!DumpMempool(mempool)) {
        throw JSONRPCError(RPC_MISC_ERROR, "Unable to dump mempool to disk");
    }
    return NullUniValue;
},
    };
}
namespace {
bool FindScriptPubKey(std::atomic<int>& scan_progress, const std::atomic<bool>& should_abort, int64_t& count, CCoinsViewCursor* cursor, const std::set<CScript>& needles, std::map<COutPoint, Coin>& out_results, std::function<void()>& interruption_point)
{
    scan_progress = 0;