Checkpoint
DVPL-4857: splunk-sdk-csharp-pcl | Feature | Implement SearchResultStream and SearchPreviewStream as cold observables with blocking enumerator
Resolved swith 100% test pass against an improved set of acceptance tests. See CanCancelExportSearchPreviews, CanCancelExportSearchResults, CanExportSearchPreviewsToEnumerable,  CanExportSearchPreviewsToObservable,  CanExportSearchResultsToEnumerable,  and CanExportSearchResultsToObservable.