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",