[Windows] Fix Shell.Flyout menu disappears when pressing Alt key

[Foda]

Description of Change

Remove MeasureOverride and ArrangeOverride from `ShellFlyoutItemView. It's not clear why it exists, but it is the source of the issue.

The issue is caused by the logic in both of these functions not invoking base.ArrangeOverride and base.MeasureOverride.

Issues Fixed

Fixes #23214