Add java API to get size of host memory needed to copy column view

[revans2]

Description

To help with work for host memory management in java this provides an API to know how much memory is needed on the host to copy the data before it happens.

This was written by @jbrennan333 but I am taking over the patch to get it in.

Checklist

• I am familiar with the Contributing Guidelines.
• New or existing tests cover these changes.
• The documentation is up to date with these changes.

[revans2]

@gerashegalov and @ttnghia sorry to change the code on you. I realized that we already had some C++ code to do almost the exact same thing, so I switched over to use it instead. Just to remove duplication.

[gerashegalov]

LGTM, just optional nits

[revans2]

Great catch @razajafri I updated the code to follow the alignment that C++ says it should be. Turns out, at least for my desktop, it is 32-byte aligned. So 64-bytes was not too far off for what we really wanted.

[razajafri]

build

[revans2]

/merge