[C++] Implement kernels for in-place sorting of fixed-width contiguous arrays

[asfimport]

See discussion in #2112. A kernel may want to throw if the memory being sorted is shared (in which case the user should copy, then sort)

Sorting of chunked data is a more complex topic so that's out of scope for this task

Reporter: Wes McKinney / @wesm

Related issues:

• [C++] Implement serial version of sort computational kernel (is related to)

_{Note: This issue was originally created as ARROW-2685. Please see the migration documentation for further details.}

[asfimport]

Wes McKinney / @wesm:
Since we have SortToIndices and Arrow arrays have immutable semantics, this should be solved a different way