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ARROW-16824: [C++] Migrate VectorKernels to use ExecSpan, split out ChunkedArray execution (#13398)

This is mostly mechanical refactoring. Since many VectorKernels support being passed in a ChunkedArray, I separated the `ExecSpan` code path (which does not support chunked arrays) from a separate `VectorKernel::exec_chunked` function which continues to use the `const ExecBatch&` input format. 

Aggregate (scalar and hash) kernels will have to get refactored in a follow up PR. I was going to try to pack that into this branch but it got to be a little bit too much. I would like to work on ARROW-16757 next anyway which will help a lot with cleaning up a lot of accumulated cruft

I also removed the "scalar" input mode of "cumulative_sum" because the result was ill-defined per a separate discussion.

Authored-by: Wes McKinney <wesm@apache.org>
Signed-off-by: Wes McKinney <wesm@apache.org>