A user reported to me that they are unable to create a PSBT with a legacy watchonly wallet when they use the GUI. They get an error "The amount exceeds your balance".

I think the issue is that the GUI will retrieve the wallet's balance via `AvailableCoins` before calling `CreateTransaction`. This call to `AvailableCoins` is resulting in fewer coins being returned with recent changes to how `AvailableCoins` works, particularly with additional filtering of spendable coins and preset coins.

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Note that this does not effect descriptor wallets. A workaround for this issue is to switch to using descriptor wallets. An existing legacy wallet can be turned into a descriptor wallet using the `migratewallet` RPC. However many watchonly legacy wallets are likely the result of importing descriptors via `importmulti`. For such wallets, I recommend creating a new descriptor wallet and re-importing the descriptors.
{
                return InvalidAddress;
            }
            if(rcp.amount <= 0)
            {
                return InvalidAmount;
            }
            setAddress.insert(rcp.address);
            ++nAddresses;
            CScript scriptPubKey = GetScriptForDestination(DecodeDestination(rcp.address.toStdString()));
            CRecipient recipient = {scriptPubKey, rcp.amount, rcp.fSubtractFeeFromAmount};
            vecSend.push_back(recipient);
            total += rcp.amount;
        }
    }
    if(setAddress.size() != nAddresses)
    {
        return DuplicateAddress;
    }
    
    
    CAmount nBalance = getAvailableBalance(&coinControl);
    if(total > nBalance)
    {
        return AmountExceedsBalance;
    }
    try {
        CAmount nFeeRequired = 0;
        int nChangePosRet = -1;
        auto& newTx = transaction.getWtx();