message: rpc: Improve scantxoutset response and help message
diff: @@ -2199,11 +2199,15 @@ UniValue scantxoutset(const JSONRPCRequest& request)
  },
  RPCResult{
  "{\n"
  + " \"success\": true|false, (boolean) Whether the scan was completed\n"
  + " \"txouts\": n, (numeric) The number of unspent transaction outputs scanned\n"
  + " \"height\": n, (numeric) The current block height (index)\n"
  + " \"bestblock\": \"hex\", (string) The hash of the block at the tip of the chain\n"
  " \"unspents\": [\n"
  " {\n"
  - " \"txid\" : \"transactionid\", (string) The transaction id\n"
  - " \"vout\": n, (numeric) the vout value\n"
  - " \"scriptPubKey\" : \"script\", (string) the script key\n"
  + " \"txid\": \"hash\", (string) The transaction id\n"
  + " \"vout\": n, (numeric) The vout value\n"
  + " \"scriptPubKey\": \"script\", (string) The script key\n"
  " \"desc\": \"descriptor\", (string) A specialized descriptor for the matched scriptPubKey\n"
  " \"amount\": x.xxx, (numeric) The total amount in " + CURRENCY_UNIT + " of the unspent output\n"
  " \"height\": n, (numeric) Height of the unspent transaction output\n"
  @@ -2293,15 +2297,20 @@ UniValue scantxoutset(const JSONRPCRequest& request)
  g_scan_progress = 0;
  int64_t count = 0;
  std::unique_ptr<CCoinsViewCursor> pcursor;
  + CBlockIndex* tip;
  {
  LOCK(cs_main);
  ::ChainstateActive().ForceFlushStateToDisk();
  pcursor = std::unique_ptr<CCoinsViewCursor>(pcoinsdbview->Cursor());
  assert(pcursor);
  + tip = ::ChainActive().Tip();
  + assert(tip);
  }
  bool res = FindScriptPubKey(g_scan_progress, g_should_abort_scan, count, pcursor.get(), needles, coins);
  result.pushKV("success", res);
  - result.pushKV("searched_items", count);
  + result.pushKV("txouts", count);
  + result.pushKV("height", tip->nHeight);
  + result.pushKV("bestblock", tip->GetBlockHash().GetHex());
  for (const auto& it : coins) {
  const COutPoint& outpoint = it.first;
  