External inputs are currently only supported for initial transaction creation functions. Extend `solving_data` arguments as necessary to support fee bumping wallet transactions with non-wallet inputs.

https://github.com/bitcoin/bitcoin/pull/17211#issuecomment-897653994
WalletValueMap value_map,
        WalletOrderForm order_form) override
    {
        LOCK(m_wallet->cs_wallet);
        m_wallet->CommitTransaction(std::move(tx), std::move(value_map), std::move(order_form));
    }
    bool transactionCanBeAbandoned(const uint256& txid) override { return m_wallet->TransactionCanBeAbandoned(txid); }
    bool abandonTransaction(const uint256& txid) override
    {
        LOCK(m_wallet->cs_wallet);
        return m_wallet->AbandonTransaction(txid);
    }
    bool transactionCanBeBumped(const uint256& txid) override
    {
        return feebumper::TransactionCanBeBumped(*m_wallet.get(), txid);
    }
    bool createBumpTransaction(const uint256& txid,
        const CCoinControl& coin_control,
        std::vector<bilingual_str>& errors,
        CAmount& old_fee,
        CAmount& new_fee,
        CMutableTransaction& mtx) override
    {
        return feebumper::CreateRateBumpTransaction(*m_wallet.get(), txid, coin_control, errors, old_fee, new_fee, mtx) == feebumper::Result::OK;
    }
    bool signBumpTransaction(CMutableTransaction& mtx) override { return feebumper::SignTransaction(*m_wallet.get(), mtx); }