Describe the bug
When using the built-in native TypeScript transpiler, the extends field is not supported and only the explicit compilerOptions are used. This field is sometimes used in monorepos to extend a shared config, or to extend one of the official "base" templates.

To Reproduce
Steps to reproduce the behavior:
0. Install a base config: npm install @tsconfig/node16

1. Create a tsconfig.json extending that config:

{
  "extends": "@tsconfig/node16/tsconfig.json"
}

2. Create a Dangerfile which tries to use non-commonjs features:

import { exec } from "child_process";

3. Try to run Danger with danger ci. It will report an error like "cannot use import outside a module", as the module: "commonjs" option from the base config does not get inherited correctly.

Expected behavior
Danger should support all official methods of configuring tsconfig.json.

Additional context
I believe the bug is because Danger's transpiler directly loads the tsconfig file contents and passes it to ts.transpileModule:

This can be fixed by using the TypeScript APIs for parsing the config options. For example, in ts-node:
https://github.com/TypeStrong/ts-node/blob/14323f9d00d5c7051ac09b944c7f423e442145ea/src/configuration.ts#L301-L317

Some of the other functions in this file, like lookupTSConfig, can also use the native APIs instead.