worker.Manager: add controllerchange SW listener as early as possible

@dfabulich not sure, if you are still using your old code:

var refreshing;
navigator.serviceWorker.addEventListener('controllerchange',
    function () {
        if (refreshing) return;
        refreshing = true;
        window.location.reload();
    }
);

https://developer.mozilla.org/en-US/docs/Web/API/EventTarget/addEventListener => the support for options.once was already there in 2017, so i guess we can simplify it to:

navigator.serviceWorker.addEventListener('controllerchange', function() {
    window.location.reload()
}, {once: true});

Yes, {once: true} is the right way to do it now, and I've just updated my blog post to match.

FWIW, options.once was not widely available in 2017. I'm not sure it worked at all in pre-Chromium Edge, which means it didn't become newly available until Edge 18 (based on Chromium) in 2018, and didn't reach "widely available" Baseline until 30 months after that, April 2021.

@dfabulich Since commits are not easy to track, the idea of what i am doing here:

Abstract base class: https://github.com/neomjs/neo/blob/dev/src/worker/Base.mjs

This one get used / extended inside apps & examples: https://github.com/neomjs/neo/blob/dev/apps/ServiceWorker.mjs

Workspaces for devs to create apps via npx neo-app@latest follow the exact same structure, so devs can easily override or extend the class as needed (e.g. customising what to cache).

The clue here is that the SW will create a MessageChannel and pass the 2nd port through a main-thread to the either dedicated or shared application worker. Combined with remote method access, this allows predictive caching at run-time.

Browser support has luckily evolved a lot during the last years: I still remember too well that in 2018 I had to use a chrome experimental flag to get dedicated workers use JS modules (run without builds). It took more years until the same was in place for SharedWorker. Updating the blog post sounds like a good idea. There is still very little to find about SWs online.

Best regards, Tobi