message: test: non-addrman unit tests: override-able check ratio
  Make it possible to override from the command line (without recompiling)
  the addrman check ratio in the common `TestingSetup::m_node::addrman`
  (used by all unit tests) instead of hardcoding it to 0:
  ```
  test_bitcoin --run_test="transaction_tests/tx_valid" -- -checkaddrman=1
  ```
diff: @@ -223,7 +223,9 @@ TestingSetup::TestingSetup(const std::string& chainName, const std::vector<const
  throw std::runtime_error(strprintf("ActivateBestChain failed. (%s)", state.ToString()));
  }
  - m_node.addrman = std::make_unique<AddrMan>(/*asmap=*/std::vector<bool>(), /*deterministic=*/false, /*consistency_check_ratio=*/0);
  + m_node.addrman = std::make_unique<AddrMan>(/*asmap=*/std::vector<bool>(),
  + /*deterministic=*/false,
  + m_node.args->GetIntArg("-checkaddrman", 0));
  m_node.banman = std::make_unique<BanMan>(m_args.GetDataDirBase() / "banlist", nullptr, DEFAULT_MISBEHAVING_BANTIME);
  m_node.connman = std::make_unique<CConnman>(0x1337, 0x1337, *m_node.addrman); // Deterministic randomness for tests.
  m_node.peerman = PeerManager::make(chainparams, *m_node.connman, *m_node.addrman,
  