Deprecate ArrayHandle::GetDeviceAdapterId

This method is a remenant of when `ArrayHandle` could only store data on
one device at a time. It is now capable of storing data on any number of
devices (as well as the host), so asking for "the" device no longer
makes sense. Thus, this method is deprecated in favor of
`ArrayHandle::IsOnDevice`.

This deprecation leads to fixing some older functionality that still
assumed data could only be on one device at a time.

Fixes #592.