* Add samples for AppConfig LRO CreateSnapshot with comparisons of what we'd expect the user experience to be.
* Add the necessary thread include.
* Update LRO sample where Operation<T> returns a status monitor instead of the resource.
* Add initial result to get the snapshot back from the first request, and fix formatting.
* Update the return type of GetSnapshot to match existing, current API shape.
* Add samples for all AppConfig pager methods (GetSnapshots, GetConfigurationSettings, GetRevisions) with comparisons of what we'd expect the user experience to be.
* Adding GetConfigurationSettings for snapshot.
