[REQ] [typescript-*] add flag to don't convertation some types

Created by: gormonn

Hello! I partially use your wonderful tool to generate types for redux-toolkit-query. More details can be found here: https://github.com/rtk-incubator/rtk-query-codegen/issues/63#issuecomment-879219548

However, when the API changes, I have to compare the new generated files with the old ones. For example, since Redux prefers to store serializable data, I need to rewrite the generated date to string types, and then I need to rewrite some functions that convert strings to dates. From:

interface Car {
  id: string;
  yearOfManufacture: Date;
}
function CarFromJSON(json: any): Car {
  return {
    id: json['id'],
    yearOfManufacture: new Date(json['year_of_manufacture']),
  };
}

To:

interface Car {
  id: string;
  yearOfManufacture: string;
}
function CarFromJSON(json: any): Car {
  return {
    id: json['id'],
    yearOfManufacture: json['year_of_manufacture'],
  };
}

So... With each new iteration, the number of models grows, and such differences between the generated types and the actual ones remain. This makes Diff very difficult.

What I suggest: Perhaps there is a way to make the generator behavior customizable? For example for data serializability.