Use ESRP release and private npm registry in publish build

[Elizabeth Craig (ecraig12345)]

Description of changes

Use the ESRP release API wrapper (@microsoft/esrp-npm-release) I wrote for publishing. That link has more details about the overall approach, and this pipeline uses the same resources I already set up for the beachball repo's release.

New publishing workflow:

• Use a private Office npm registry to avoid network isolation issues
• Build stage:
  • yarn lage pack packs new package versions (same as before) but organizes the tgz files into the required format for the tool
    • Also pack them under Build.StagingDirectory so that can be used as the publish pipeline's outputParentDirectory to only run SDL tasks once
  • Upload packs and @microsoft/esrp-npm-release CLI as artifacts (the CLI must be an artifact so it's accessible to the release job, which can't npm install)
    • Temporary workaround: due to quarantine on the internal feed, the CLI is temporarily checked in as scripts/esrp-npm-release-temp/index.mjs
• Publish stage:
  • Download CLI and tarball artifacts
  • Get credentials
  • Use CLI to publish with ESRP

Verification

• Ran the ADO pipeline against my branch (with publishing step commented)
• PR build passes