[C++] Numeric kernel implementations for add (+)

[asfimport]

This function should respect consistent type promotions between types of different sizes and signed and unsigned integers

Reporter: Wes McKinney / @wesm
Assignee: Artem Alekseev / @fexolm

PRs and other links:

• GitHub Pull Request #5021

_{Note: This issue was originally created as ARROW-1562. Please see the migration documentation for further details.}

[asfimport]

Francois Saint-Jacques / @fsaintjacques:
Issue resolved by pull request 5021
#5021