message: node/ifaces: NodeImpl: Use existing NodeContext member
diff: @@ -180,18 +180,21 @@ public:
  int getNumBlocks() override
  {
  LOCK(::cs_main);
  - return ::ChainActive().Height();
  + assert(std::addressof(::ChainActive()) == std::addressof(m_context->chainman->ActiveChain()));
  + return m_context->chainman->ActiveChain().Height();
  }
  uint256 getBestBlockHash() override
  {
  - const CBlockIndex* tip = WITH_LOCK(::cs_main, return ::ChainActive().Tip());
  + assert(std::addressof(::ChainActive()) == std::addressof(m_context->chainman->ActiveChain()));
  + const CBlockIndex* tip = WITH_LOCK(::cs_main, return m_context->chainman->ActiveChain().Tip());
  return tip ? tip->GetBlockHash() : Params().GenesisBlock().GetHash();
  }
  int64_t getLastBlockTime() override
  {
  LOCK(::cs_main);
  - if (::ChainActive().Tip()) {
  - return ::ChainActive().Tip()->GetBlockTime();
  + assert(std::addressof(::ChainActive()) == std::addressof(m_context->chainman->ActiveChain()));
  + if (m_context->chainman->ActiveChain().Tip()) {
  + return m_context->chainman->ActiveChain().Tip()->GetBlockTime();
  }
  return Params().GenesisBlock().GetBlockTime(); // Genesis block's time of current network
  }
  @@ -200,11 +203,15 @@ public:
  const CBlockIndex* tip;
  {
  LOCK(::cs_main);
  - tip = ::ChainActive().Tip();
  + assert(std::addressof(::ChainActive()) == std::addressof(m_context->chainman->ActiveChain()));
  + tip = m_context->chainman->ActiveChain().Tip();
  }
  return GuessVerificationProgress(Params().TxData(), tip);
  }
  - bool isInitialBlockDownload() override { return ::ChainstateActive().IsInitialBlockDownload(); }
  + bool isInitialBlockDownload() override {
  + assert(std::addressof(::ChainstateActive()) == std::addressof(m_context->chainman->ActiveChainstate()));
  + return m_context->chainman->ActiveChainstate().IsInitialBlockDownload();
  + }
  bool getReindex() override { return ::fReindex; }
  bool getImporting() override { return ::fImporting; }
  void setNetworkActive(bool active) override
  @@ -228,7 +235,8 @@ public:
  bool getUnspentOutput(const COutPoint& output, Coin& coin) override
  {
  LOCK(::cs_main);
  - return ::ChainstateActive().CoinsTip().GetCoin(output, coin);
  + assert(std::addressof(::ChainstateActive()) == std::addressof(m_context->chainman->ActiveChainstate()));
  + return m_context->chainman->ActiveChainstate().CoinsTip().GetCoin(output, coin);
  }
  WalletClient& walletClient() override
  {
  