Add ngrok flag to dev

[michenly]

WHY are these changes introduced?

This PR is intended to make development easier by adding a ngrok flag to shopify hydrogen dev

WHAT is this pull request doing?

HOW to test your changes?

Test by using changing dev script to run shopify hydrogen dev --codegen --ngrok --ngrok-auth-token=<your-ngrok-auth-token> --ngrok-domain=<your-ngrok-domain>

or using shopify hydrogen dev --codegen --ngrok with two environment variables in .env file

in .env

NGROK_AUTHTOKEN=<your-ngrok-auth-token>
NGROK_DOMAIN=<your-ngrok-domain>

Next

• add ngrok domain to CSP automatically
• taking the ngrok url and changing them in admin using an API? (does this exist?)

Checklist

• I've read the Contributing Guidelines
• I've considered possible cross-platform impacts (Mac, Linux, Windows)
• I've added a changeset if this PR contains user-facing or noteworthy changes
• I've added tests to cover my changes
• I've added or updated the documentation