[C++][Parquet] Incorporate DELTA_BYTE_ARRAY value encoder into library and add unit tests

[asfimport]

See examples/decode_benchmark.cc

Reporter: Wes McKinney / @wesm
Assignee: Shan Huang / @shanhuuang

Related issues:

• [C++] Read DELTA_BYTE_ARRAY data written with bug PARQUET-246 (relates to)

PRs and other links:

• GitHub Pull Request #10978
• GitHub Pull Request #20

_{Note: This issue was originally created as PARQUET-492. Please see the migration documentation for further details.}

[asfimport]

Antoine Pitrou / @pitrou:
Issue resolved by pull request 10978
#10978