Adds Support for ObservableCollection<T> and Collection<T> Range APIs from dotnet/runtime#6097

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SkyeHoefling wants to merge 1 commit intodotnet:mainfrom

SkyeHoefling:oc_range_apis

Commits on Feb 9, 2022

Removes exceptions when CollectionChanges is != 1; This allows AddRange() and RemoveRange() apis for ObservableCollection
SkyeHoefling
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