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
{
    
    
    wallet.BlockUntilSyncedToCurrentChain();
    change_position = -1;
    bool lockUnspents = false;
    UniValue subtractFeeFromOutputs;
    std::set<int> setSubtractFeeFromOutputs;
    if (!options.isNull()) {
      if (options.type() == UniValue::VBOOL) {
        
        coinControl.fAllowWatchOnly = options.get_bool();
      }
      else {
        RPCTypeCheckArgument(options, UniValue::VOBJ);
        RPCTypeCheckObj(options,
            {
                {"add_inputs", UniValueType(UniValue::VBOOL)},
                {"include_unsafe", UniValueType(UniValue::VBOOL)},
                {"add_to_wallet", UniValueType(UniValue::VBOOL)},
                {"changeAddress", UniValueType(UniValue::VSTR)},
                {"change_address", UniValueType(UniValue::VSTR)},
                {"changePosition", UniValueType(UniValue::VNUM)},
                {"change_position", UniValueType(UniValue::VNUM)},
                {"change_type", UniValueType(UniValue::VSTR)},
                {"includeWatching", UniValueType(UniValue::VBOOL)},
                {"include_watching", UniValueType(UniValue::VBOOL)},