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 MakeSignalHandler(m_wallet->NotifyStatusChanged.connect([fn](CWallet*) { fn(); }));
    }
    std::unique_ptr<Handler> handleAddressBookChanged(AddressBookChangedFn fn) override
    {
        return MakeSignalHandler(m_wallet->NotifyAddressBookChanged.connect(
            [fn](const CTxDestination& address, const std::string& label, bool is_mine,
                 const std::string& purpose, ChangeType status) { fn(address, label, is_mine, purpose, status); }));
    }
    std::unique_ptr<Handler> handleTransactionChanged(TransactionChangedFn fn) override
    {
        return MakeSignalHandler(m_wallet->NotifyTransactionChanged.connect(
            [fn](const uint256& txid, ChangeType status) { fn(txid, status); }));
    }
    std::unique_ptr<Handler> handleWatchOnlyChanged(WatchOnlyChangedFn fn) override
    {
        return MakeSignalHandler(m_wallet->NotifyWatchonlyChanged.connect(fn));
    }
    std::unique_ptr<Handler> handleCanGetAddressesChanged(CanGetAddressesChangedFn fn) override
    {
        return MakeSignalHandler(m_wallet->NotifyCanGetAddressesChanged.connect(fn));
    }
    CWallet* wallet() override { return m_wallet.get(); }
    WalletContext& m_context;
    std::shared_ptr<CWallet> m_wallet;
};
class WalletLoaderImpl : public WalletLoader