fix: sync status not updating correctly

[DominicGBauer]

Description

There was an issue where hasSynced was being reset after becoming true. This issue was due to the update function in the SyncStatus class using the copy method and expecting default values to be persisted. However when the update function is run and copy is invoked it does not know about the default values in the update function so it overwrites the previous values with null.

This fixes the issue by not relying on default values from the update function.

Previously

status = { connected: true, hasSynced: true }

status.update(connected:false)

status = { connected false, hasSynced: null }

Now

status = { connected: true, hasSynced: true }

status.update(connected:false)

status = { connected false, hasSynced: true }

I have also included an example implementation of using hasSynced in the demo.

Testing

Implemented the change in the demo and tested to confirm it shows "busy syncing..." when hasSynced is not true and shows the content otherwise