Treat every line of input as a single String field.
Similar to `JSONAsString`.
{
    auto & target = dict[name].input_creator;
    if (target)
        throw Exception("FormatFactory: Input format " + name + " is already registered", ErrorCodes::LOGICAL_ERROR);
    target = std::move(input_creator);
}
void FormatFactory::registerOutputFormat(const String & name, OutputCreator output_creator)
{
    auto & target = dict[name].output_creator;
    if (target)
        throw Exception("FormatFactory: Output format " + name + " is already registered", ErrorCodes::LOGICAL_ERROR);
    target = std::move(output_creator);
}
void FormatFactory::registerInputFormatProcessor(const String & name, InputProcessorCreator input_creator)