Merge bitcoin#19370: Static asserts for consistency of fee defaults

1554b54 Static asserts for consistency of fee defaults. (Daniel Kraft)

Pull request description:

  This adds `static_assert`'s that ensure that the default values given for fee levels in the wallet (minimum fee and incremental feerate increase) are at least as high as the corresponding levels configured in the core node policy.  Since the core policy values are enforced by the network, it makes sense for the wallet to be conservative and above (or at least not below) this.

ACKs for top commit:
  laanwj:
    code review ACK 1554b54, these assumptions seem straightforward

Tree-SHA512: 50e5adf082f467062334377f82a3ee75bcfd436afc65bd0eb33c8d0549d6d90fd1f48c31f60cabe523eb59be9efa8ae0879e9e09cd51ca9c1bd466631ce03cf4

src/wallet/test/wallet_tests.cpp

@@ -36,6 +36,11 @@ extern UniValue addmultisigaddress(const JSONRPCRequest& request);
 
 extern RecursiveMutex cs_wallets;
 
+// Ensure that fee levels defined in the wallet are at least as high
+// as the default levels for node policy.
+static_assert(DEFAULT_TRANSACTION_MINFEE >= DEFAULT_MIN_RELAY_TX_FEE, "wallet minimum fee is smaller than default relay fee");
+static_assert(WALLET_INCREMENTAL_RELAY_FEE >= DEFAULT_INCREMENTAL_RELAY_FEE, "wallet incremental fee is smaller than default incremental relay fee");
+
 BOOST_FIXTURE_TEST_SUITE(wallet_tests, WalletTestingSetup)
 
 namespace {