Also enables the frontend not asking for notiffication permission if it
doesn't need them.
Should also help if it ever needs to be changed to circumvent cache.
- Move push subscription handling to Notifier class
- Allow duplicate options in config
- Only save subscription in frontend if sub call was successful
Includes requesting permissions and adding a basic service worker
as well as re-working and restructuring a bunch of the existing logic
for parsing URL parameters, sending data and adding another form field
Oskar Winkels