🛎️ 🔄️ Improve notifications of file changes from notify_push server app

[mgallien]

Currently desktop client will register to notification from server for changes to files to immediately synchronize changes instead of polling for them.
In case we receive a notification, desktop client will need to discover them.
It would be better to register for notifications with more information (using listen notify_file_id).
Most of the time that would give more information to desktop files client being able to then shortcut the sync and do it quicker and using less server resources.

[mgallien]

@AndyScherzinger @tobiasKaminsky

[marcotrevisan]

Just linking related issues to this one: #5072, nextcloud/notify_push#192

[marcotrevisan]

By the way I didn't fully understand the HPB related comments in #5072, and after all in my humble opinion, the client should not need further pieces of server architecture to work properly with push notifications...

[AndyScherzinger]

@marcotrevisan there won't be any further server pieces here. The HPB can supply further details on changes files/folders which would improve the sync logic on the client not having to create the number of profinds it does today.