This PR improves the sync time estimation flow

Basic changes:

• Improves sync time estimation flow as follows:
  • in addition to existing emitting WS events when the next collection is syncing to not hold the previous time value (some collections can sync very long) adds an ability to emit the progress event every 1sec with new values spentTime and leftTime for better UX (so that the user does not think that sync has stalled)
• Changes sync progress test case
• Returns sync estimated time values as an integer after calculation