Issue Summary

While it is known that data preparation may take some time - hours or even days - there is no feedback of the status of the data preparation other than a spinning wheel.

Suggestion

The data preparation pre-flight check should provide more detailed feedback to guide administrators on where the check is at.

Currently, users see:

The pre-flight check involves more than one data check. It would be nice if each of these data checks was given its own progress bar/spinner. Where possible, for larger checks (where the pre-flight check has assessed that 10000+ entities are involved), it would be helpful to give a ballpark indicator to say that the first 1000 of 10000+ entities have been checked.

This would allow admins to more confidently apply dark features, knowing that some preflight checks have already been passed and do not need further attention in future migration plans.