feat(dev-infra): integrate merge script into ng-dev cli (#37138)

Integrates the merge script into the `ng-dev` CLI. The goal is that
caretakers can run the same command across repositories to merge a pull
request. The command is as followed: `yarn ng-dev pr merge <number>`.

PR Close #37138

dev-infra/utils/BUILD.bazel

@@ -7,6 +7,7 @@ ts_library(
     visibility = ["//dev-infra:__subpackages__"],
     deps = [
         "@npm//@octokit/graphql",
+        "@npm//@types/inquirer",
         "@npm//@types/node",
         "@npm//@types/shelljs",
         "@npm//shelljs",

dev-infra/utils/config.ts

@@ -9,13 +9,20 @@
 import {join} from 'path';
 import {exec} from 'shelljs';
 
+/**
+ * Describes the Github configuration for dev-infra. This configuration is
+ * used for API requests, determining the upstream remote, etc.
+ */
+export interface GithubConfig {
+  /** Owner name of the repository. */
+  owner: string;
+  /** Name of the repository. */
+  name: string;
+}
+
 /** The common configuration for ng-dev. */
 type CommonConfig = {
-  /* Github repository configuration used for API Requests, determining upstream remote, etc. */
-  github: {
-    owner: string,
-    name: string,
-  }
+  github: GithubConfig
 };
 
 /**

dev-infra/utils/console.ts

@@ -0,0 +1,20 @@
+/**
+ * @license
+ * Copyright Google LLC All Rights Reserved.
+ *
+ * Use of this source code is governed by an MIT-style license that can be
+ * found in the LICENSE file at https://angular.io/license
+ */
+
+import {prompt} from 'inquirer';
+
+/** Prompts the user with a confirmation question and a specified message. */
+export async function promptConfirm(message: string, defaultValue = false): Promise<boolean> {
+  return (await prompt<{result: boolean}>({
+           type: 'confirm',
+           name: 'result',
+           message: message,
+           default: defaultValue,
+         }))
+      .result;
+}