feat(dev-infra): add release command for setting NPM dist tag (#38656)

Introduces a new command for `ng-dev release`, so that the NPM
dist tag can be set for all configured NPM packages. This command
can be useful in case a manual tag needs to be set, but it is
primarily used by the release tooling when a new stable version
is cut, and when the previous patch branch needs to be set as LTS
version through a `v{major}-lts` dist tag.

It is necessary to have this as a command so that the release tool
can execute it for old branches where other packages might have been
configured. This is similar to the separate `ng-dev build` command
that we created.

Note that we also added logic for spawning a process conveniently
with different "console output" modes. This will be useful for
other command invocations in the release tool and it's generally
better than directly using native `child_process` as that one doesn't
log to the dev-infra debug log file.

PR Close #38656

dev-infra/release/versioning/npm-publish.ts

@@ -0,0 +1,24 @@
+/**
+ * @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 * as semver from 'semver';
+import {spawnWithDebugOutput} from '../../utils/child-process';
+
+/**
+ * Sets the NPM tag to the specified version for the given package.
+ * @throws With the process log output if the tagging failed.
+ */
+export async function setNpmTagForPackage(
+    packageName: string, distTag: string, version: semver.SemVer, registryUrl: string|undefined) {
+  const args = ['dist-tag', 'add', `${packageName}@${version}`, distTag];
+  // If a custom registry URL has been specified, add the `--registry` flag.
+  if (registryUrl !== undefined) {
+    args.push('--registry', registryUrl);
+  }
+  await spawnWithDebugOutput('npm', args, {mode: 'silent'});
+}