Feature summary (what you would like to be able to do and where):

It should be possible for a user to receive notifications through their web browser. This notification preference shall follow the "Apps" preference for notifications. A link in Preferences can allow the user to enable notifications through their web browser to support this feature. This might necessitate a service worker to listen for notifications and then push them to the notification tray on Windows/macOS/iOS/Android where upon clicking the relevant notification is opened on the wiki.

Use case(s) (list the steps that you performed to discover that problem, and describe the actual underlying problem which you want to solve. Do not describe only a solution):

Currently notifications are only fetched on page load. This requires users to continuously log onto (and refresh pages on) a wiki to see what has changed. A service worker can potentially allow both the aforementioned behavior and allow updating of the icons inserted by Echo as notifications are marked as read.

Benefits (why should this be implemented?):

This allows users to receive notifications for different wikis when they are not actively viewing the site.