Code Quality: Optimize large folder enumeration performance

[workbysaran]

Resolved / Related Issues

Fixed performance issues when enumerating large folders that would cause the UI to freeze or become unresponsive during folder scanning operations.

Steps used to test these changes

1. Open the Files app and navigate to a directory containing a large number of files (100,000+).
2. Observe the folder enumeration process and UI responsiveness.
3. The UI remains responsive during large folder operations without freezing.

[Josh65-2201]

It could be confusing to people that this folder is empty is shown for a few seconds while it loading. That doesn't happen in v4.0.11

[yaira2]

It seems to me that C:\Windows\WinSxS takes longer to load with these changes.