[C++] Consolidate files dealing with row-major storage, add some helper methods

[asfimport]

We've built up a number of utilities that are based around a row-major encoding. Understanding these utilities requires a pretty in-depth understanding of this encoding format.

In addition, as we start to have external work done on exec nodes I think some of these utilities will be useful to eventually expose externally.

This JIRA is for work to refactor the existing row-based utilities and consolidate them into a separate location.

Reporter: Weston Pace / @westonpace
Assignee: Weston Pace / @westonpace

PRs and other links:

• GitHub Pull Request #13172
• GitHub Pull Request #13218

_{Note: This issue was originally created as ARROW-16590. Please see the migration documentation for further details.}

[asfimport]

Wes McKinney / @wesm:
Issue resolved by pull request 13218
#13218