Add a pair of variadic functions equivalent to SQL's least/greatest or R's pmin/pmax. Should take 0, 1, 2, ... same-length numeric arrays as input and return an array giving the minimum/maximum of the values found in each position of the input arrays. For example, in the case of these 2 input arrays:

Array<double>        Array<double>
[                    [
  1,                   2,
  4                    3
]                    ]

least would return:

Array<double>
[ 
  1,
  3
] 

and greatest would return

Array<double>
[ 
  2,
  4
] 

The returned array should have the same data type as the input arrays, or follow promotion rules if the numeric types of the input arrays differ.

Should also accept scalar numeric inputs and recycle their values.

Reporter: Ian Cook / @ianmcook
Assignee: David Li / @lidavidm

Related issues:

• [C++] Arithmetic kernels for numeric arrays (is a child of)
• [R] Add bindings for pmin() and pmax() (is depended upon by)

PRs and other links:

• GitHub Pull Request #10390

_{Note: This issue was originally created as ARROW-12751. Please see the migration documentation for further details.}