add: support source maps for tsx

[tomzacchia]

As describe in this babel-loader issue this configuration is needed to see/debug original code in devtools > soruces

// DummyComponent.tsx in DevTools when sourceMap: false

"use strict";
var __importDefault = (this && this.__importDefault) || function (mod) {
    return (mod && mod.__esModule) ? mod : { "default": mod };
};
exports.__esModule = true;
var react_1 = __importDefault(require("react"));
function DummyComponent() {
    return (react_1["default"].createElement("div", null,
        react_1["default"].createElement("h1", null, "hello world")));
}
exports["default"] = DummyComponent;

// DummyComponent.tsx in DevTools when sourceMap: true

import React from 'react';

function DummyComponent() {
  return (
    <div>
      <h1>hello world</h1>
    </div>
  );
}

export default DummyComponent;