Install new service worker by clicking a button

[jackdbd]

See:

• https://youtu.be/cmRqQJBIp_A?t=1085
• https://developer.mozilla.org/en-US/docs/Web/API/ServiceWorkerRegistration/update
• https://developers.google.com/web/fundamentals/primers/service-workers/lifecycle#manual_updates
• https://whatwebcando.today/articles/handling-service-worker-updates/
• https://redfin.engineering/how-to-fix-the-refresh-button-when-using-service-workers-a8e27af6df68