[Push API] Wait to trigger the events until the device is online

Hello!

In the spec <https://www.w3.org/TR/push-api/> I cannot find anything about
the network status (device online / offline).

The events triggered by the Push API (i.e. push, pushsubscriptionchange)
always require an internet connection in order to talk with the application
server (e.g. send delivery receipts, send new endpoint to server, download
notifications) or to display the notification (e.g. download icon, image).

I think that the browser should (MUST) wait to trigger those events
until the device is online, so that those events can be processed properly
without exceptions from fetch.
What do you think?



Marco Colli
https://pushpad.xyz