[C++] Left/right/center string padding kernels

[asfimport]

Similar to SQL lpad/rpad or Python ljust/rjust

Reporter: Ian Cook / @ianmcook
Assignee: David Li / @lidavidm
Watchers: Rok Mihevc / @rok

Related issues:

• [C++] String algorithm library for StringArray/BinaryArray (is a child of)
• [R] Add binding for str_pad() (is depended upon by)

PRs and other links:

• GitHub Pull Request #10586

_{Note: This issue was originally created as ARROW-12716. Please see the migration documentation for further details.}

[asfimport]

Joris Van den Bossche / @jorisvandenbossche:
Python also has the center() variation to add left and right padding at the same time to center the string (https://docs.python.org/3/library/stdtypes.html#str.center)

[asfimport]

Antoine Pitrou / @pitrou:
Issue resolved by pull request 10586
#10586