fix: notification insanity

[nikkothari22]

Push notifications were being sent to the user who sent the message (only in channels - since topics)

Implemented the following:

On logging in - add current user ID to indexed DB.
On logging out - clear it.

In the service worker, fetch current user from IndexedDB and check if the message was sent by the current user. If not, create notification.

Tested this for a bit - seems to work fine. Sometimes the push notification doesn't fire (usually when the app is killed/started) - will investigate. This is hopefully not happening because of this change.

Other changes:

1. Tag all notifications with channel ID.
2. When the user opens the channel, clear the notifications.
3. For Desk integration - publish a message_update event so that it works. The desk integration needs to be updated soon with pagination, polls etc.

[nikkothari22]

Nope. Can't do this because Apple punishes silent notifications.

https://dev.to/progressier/how-to-fix-ios-push-subscriptions-being-terminated-after-3-notifications-39a7
https://meta.discourse.org/t/ios-notifications-can-lose-permission-to-push-if-the-user-is-currently-active/290225/7
firebase/firebase-js-sdk#8010

[nikkothari22]

So, now the "fix" is:

1. Show the notification. If the push is sent from the current user, then add a "silent" property to the notification.
2. After the notification is shown, close it.

[nikkothari22]

This might still cause issues if getting the data from IndexedDB takes too much time. iOS wants devs to fire a notification immediately. Possible solution: fire notification immediately and then close it afterwards.

Note: only do this if the above solution does not work.

[nikkothari22]

Looks like the only solution is to not use topic based notifications and send notifications to each user individually.