Deep copying View should use allocator id of parent

[gunney1]

There are 2 ways to deep copy data into a sidre::View, and they should allocate array data the same way.

Deep-copying from a source View currently allocates data using the destination's parent's default allocator id. However, deep-copying from a source conduit::Node, using View::importArrayNode(), currently allocates data on the host, ignoring the parent's default allocator id. We should change the second version to behave like the first.

This proposal constitutes a behavior change, which should be documented. While it is possible to copy data to the desired memory space after the deep copy, to do so for a large hierarchy is messy and wasteful.

[gunney1]

Resolved with MR #1460.