Add redundant to WorkboxLifecycleEventMap

[azizhk]

R: @jeffposnick @philipwalton
Fixes #2199

Should I add externalredundant as well? I don't think that exists right?

[philipwalton]

Thanks!

[philipwalton]

Should I add externalredundant as well? I don't think that exists right?

I think it's possible that it could be emitted by a Workbox (given the right circumstances), but it's not an event we want to promote people listening to, so we don't document it and I don't think we need to add typings for it either.

In general, as soon as there's any external* events fired, that's the point at which the user should probably refresh the page, as it usually means the version of the page they're running is out of date and things may break.

[azizhk]

In general, as soon as there's any external* events fired, that's the point at which the user should probably refresh the page"
So I don't expect the user to reload, I do window.location.reload() explicitly.

@philipwalton In the example that I have shared, before triggering skipWaiting for a SW which has multiple clients connected, I double check with the user that I will be reloading multiple tabs and he might lose data.

So similarly, in that case, I would like to have "externalredundant" event getting triggered to reload the page.

But I'll come back to this requirement based on the answer to #2199 (comment)