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.
{
    m_args.ForceSetArg("-unsafesqlitesync", "1");
    
    WalletContext context;
    context.args = &m_args;
    context.chain = m_node.chain.get();
    auto wallet = TestLoadWallet(context);
    CKey key;
    key.MakeNewKey(true);
    AddKey(*wallet, key);
    TestUnloadWallet(std::move(wallet));
    
    
    int addtx_count = 0;
    DebugLogHelper addtx_counter("[default wallet] AddToWallet", [&](const std::string* s) {
        if (s) ++addtx_count;
        return false;
    });
    bool rescan_completed = false;
    DebugLogHelper rescan_check("[default wallet] Rescan completed", [&](const std::string* s) {
        if (s) rescan_completed = true;
        return false;
    });
    
    
    
    std::promise<void> promise;
    CallFunctionInValidationInterfaceQueue([&promise] {
        promise.get_future().wait();