[Feature Request] Migrate to Workbox from sw-precache

[laurentpayot]

From Google:

Workbox is the successor to sw-precache and sw-toolbox. It is a collection of libraries and tools used for generating a service worker, precaching, routing, and runtime-caching. Workbox also includes modules for easily integrating background sync and offline Google Analytics into your service worker.

Workbox For Webpack tutorial: https://developers.google.com/web/tools/workbox/get-started/webpack

@rstoenescu I'm not doing a PR because this Feature Request is not validated yet and because this is the core of the PWA features so you might want to tweak it for the Quasar framework build process.

[rstoenescu]

Green light. Let's start with this starter kit, but eventually this work will end up in the new starter kit for v0.15: https://github.com/quasarframework/app/tree/master/template

[laurentpayot]

PR #15 for this.