Implement slice_min() and slice_max() methods for ArrowTabular, Dataset, and arrow_dplyr_query objects.

These dplyr functions supersede the older dplyr function top_n() which I suppose we should also consider implementing a method for.

Reporter: Ian Cook / @ianmcook
Assignee: Neal Richardson / @nealrichardson

Related issues:

• [R] Add slice() method (is related to)
• [C++][Compute] Implement TopK/BottomK (depends upon)

PRs and other links:

• GitHub Pull Request #14361

_{Note: This issue was originally created as ARROW-13766. Please see the migration documentation for further details.}