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
#include <script/sign.h>
#include <consensus/amount.h>
#include <key.h>
#include <policy/policy.h>
#include <primitives/transaction.h>
#include <script/keyorigin.h>
#include <script/signingprovider.h>
#include <script/standard.h>
#include <uint256.h>
#include <util/translation.h>
#include <util/vector.h>
typedef std::vector<unsigned char> valtype;
MutableTransactionSignatureCreator::MutableTransactionSignatureCreator(const CMutableTransaction& tx, unsigned int input_idx, const CAmount& amount, int hash_type)
    : m_txto{tx}, nIn{input_idx}, nHashType{hash_type}, amount{amount}, checker{&m_txto, nIn, amount, MissingDataBehavior::FAIL},
      m_txdata(nullptr)
{
}
MutableTransactionSignatureCreator::MutableTransactionSignatureCreator(const CMutableTransaction& tx, unsigned int input_idx, const CAmount& amount, const PrecomputedTransactionData* txdata, int hash_type)