(from discussion on IRC. Currently a global `settxfee` has to be changed to override the fee rate, it would make sense to be able to specify it on a per-transaction basis. This would continue #7518)

```
-*- jonasschnelli thinks we should probably add a optional feerate parameter to fundrawtransaction
<wumpus> jonasschnelli: there isn't one yet?
-*- jonasschnelli looking..
<wumpus> I'm surprised, would be so much better than changing a global
<jonasschnelli> no.. i don't think so. Maybe there is a PR.
<sipa> there is a pr
<jonasschnelli> Hard to keep track of everything. :)
<wumpus> no, the PR does it wrong
```

Regarding implementation:

```
<jonasschnelli> The ugly thing is, that CreateTransaction uses the static DEFAULT_TARGET
<wumpus> passing in an optional feerate would be the obvious thing to do
<jonasschnelli> So, this would require some refactoring.
<sipa> just add a confirmation target to coincontrol
<jonasschnelli> Yes. This sounds good.
<wumpus> right, just slap it into coincontrol
<sipa> wasn't there a PR that added a bunch of options to fundrawtransaction?
<sipa> including that
<jonasschnelli> Not the feerate.
<jonasschnelli> But the rest is merged.
```

{
    if (!EnsureWalletIsAvailable(fHelp))
        return NullUniValue;
    if (fHelp || params.size() > 1)
        throw runtime_error(
            "getrawchangeaddress\n"
            "\nReturns a new Bitcoin address, for receiving change.\n"
            "This is for use with raw transactions, NOT normal use.\n"
            "\nResult:\n"
            "\"address\"    (string) The address\n"
            "\nExamples:\n"
            + HelpExampleCli("getrawchangeaddress", "")
            + HelpExampleRpc("getrawchangeaddress", "")
       );
    LOCK2(cs_main, pwalletMain->cs_wallet);
    if (!pwalletMain->IsLocked())
        pwalletMain->TopUpKeyPool();
    CReserveKey reservekey(pwalletMain);
    CPubKey vchPubKey;
    if (!reservekey.GetReservedKey(vchPubKey))
        throw JSONRPCError(RPC_WALLET_KEYPOOL_RAN_OUT, "Error: Keypool ran out, please call keypoolrefill first");
    reservekey.KeepKey();
    CKeyID keyID = vchPubKey.GetID();
    return CBitcoinAddress(keyID).ToString();
}
UniValue setaccount(const UniValue& params, bool fHelp)