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.
{
        DatabaseOptions options;
        DatabaseStatus status;
        ReadDatabaseArgs(*m_context.args, options);
        options.require_create = true;
        options.create_flags = wallet_creation_flags;
        options.create_passphrase = passphrase;
        bilingual_str error;
        std::unique_ptr<Wallet> wallet{MakeWallet(m_context, CreateWallet(m_context, name, true, options, status, error, warnings))};
        if (wallet) {
            return {std::move(wallet)};
        } else {
            return util::Error{error};
        }
    }
    util::Result<std::unique_ptr<Wallet>> loadWallet(const std::string& name, std::vector<bilingual_str>& warnings) override
    {
        DatabaseOptions options;
        DatabaseStatus status;
        ReadDatabaseArgs(*m_context.args, options);
        options.require_existing = true;
        bilingual_str error;
        std::unique_ptr<Wallet> wallet{MakeWallet(m_context, LoadWallet(m_context, name, true, options, status, error, warnings))};
        if (wallet) {
            return {std::move(wallet)};
        } else {
            return util::Error{error};
        }
    }
    util::Result<std::unique_ptr<Wallet>> restoreWallet(const fs::path& backup_file, const std::string& wallet_name, std::vector<bilingual_str>& warnings) override