values smaller than 0.001 sat/B can't be represented by CFeeRate, but they are not rejected.

```
./src/bitcoin-cli -named sendtoaddress address=bcrt1qwkmhqum095zau5rf2velq55cq938vrd7uw8m4r amount=1.23 fee_rate=0.0009

error code: -6
error message:
Fee rate (0.000 sat/vB) is lower than the minimum fee rate setting (1.000 sat/vB)
```

```
./src/bitcoin-cli -named sendtoaddress address=bcrt1qwkmhqum095zau5rf2velq55cq938vrd7uw8m4r amount=1.23 fee_rate=0.000000000009

error code: -3
error message:
Invalid amount

{
    return RPCHelpMan{"getreceivedbyaddress",
                "\nReturns the total amount received by the given address in transactions with at least minconf confirmations.\n",
                {
                    {"address", RPCArg::Type::STR, RPCArg::Optional::NO, "The bitcoin address for transactions."},
                    {"minconf", RPCArg::Type::NUM, RPCArg::Default{1}, "Only include transactions confirmed at least this many times."},
                },
                RPCResult{
                    RPCResult::Type::STR_AMOUNT, "amount", "The total amount in " + CURRENCY_UNIT + " received at this address."
                },
                RPCExamples{
            "\nThe amount from transactions with at least 1 confirmation\n"
            + HelpExampleCli("getreceivedbyaddress", "\"" + EXAMPLE_ADDRESS[0] + "\"") +
            "\nThe amount including unconfirmed transactions, zero confirmations\n"
            + HelpExampleCli("getreceivedbyaddress", "\"" + EXAMPLE_ADDRESS[0] + "\" 0") +
            "\nThe amount with at least 6 confirmations\n"
            + HelpExampleCli("getreceivedbyaddress", "\"" + EXAMPLE_ADDRESS[0] + "\" 6") +
            "\nAs a JSON-RPC call\n"
            + HelpExampleRpc("getreceivedbyaddress", "\"" + EXAMPLE_ADDRESS[0] + "\", 6")
                },
        [&](const RPCHelpMan& self, const JSONRPCRequest& request) -> UniValue
{