ListCollectionView generating bad NewStartingIndex on LiveSorting

When using a `ListCollectionView` with live sorting enabled, occasionally the `CollectionChanged` event will emit a `NotifyCollectionChangedAction.Move` notification where the `NotifyCollectionChangedEventArgs.NewStartingIndex` property doesn't match the actual index of the item in the collection found with `ListCollectionView.IndexOf(object item)`.

If the collection view is used as an items source for a WPF component such as `ListBox`, this can result in incorrect sorting behavior or duplicate items appearing.

This seems to only occur for large collections (hundreds of items) where most of them have been marked for re-sort, presumably enough to meet `ListCollectionView.LiveSortingDensityThreshold` and trigger the `LiveShapingList.RestoreLiveSortingByInsertionSort(...)` code path.

I've attached a failing unit test demonstrating the problem. The expected behavior is that observing `CollectionChanged` events would be enough to keep an external collection in sync with the `ListCollectionView` items.

[ListCollectionViewTests.cs.txt](https://github.com/user-attachments/files/23568895/ListCollectionViewTests.cs.txt)

Start with the attached ListCollectionViewTests.cs.txt failing test and trace the LiveSorting path through LiveShapingList.RestoreLiveSortingByInsertionSort(...). Run the relevant WPF unit tests and compare CollectionChanged Move notifications with ListCollectionView.IndexOf(item); done means the reported NewStartingIndex matches the item's actual index for the large-collection scenario.

Written by the indexing model from the issue text.