message: wallet: Track scanning duration
diff: @@ -596,6 +596,7 @@ class CWallet final : public CCryptoKeyStore, private interfaces::Chain::Notific
  private:
  std::atomic<bool> fAbortRescan{false};
  std::atomic<bool> fScanningWallet{false}; // controlled by WalletRescanReserver
  + std::atomic<int64_t> m_scanning_start{0};
  std::mutex mutexScanning;
  friend class WalletRescanReserver;
  @@ -820,6 +821,7 @@ public:
  void AbortRescan() { fAbortRescan = true; }
  bool IsAbortingRescan() { return fAbortRescan; }
  bool IsScanning() { return fScanningWallet; }
  + int64_t ScanningDuration() const { return fScanningWallet ? GetTimeMillis() - m_scanning_start : 0; }
  /**
  * keystore implementation
  @@ -1241,6 +1243,7 @@ public:
  if (m_wallet->fScanningWallet) {
  return false;
  }
  + m_wallet->m_scanning_start = GetTimeMillis();
  m_wallet->fScanningWallet = true;
  m_could_reserve = true;
  return true;
  