GH-46314: [C++][Parquet] Fix valgrind error when collecting parameterized tests for MakeWKBPoint

[paleolimbot]

Rationale for this change

The nightlies for valgrind report a use of an uninitialized value around MakeWKBPointTestCase.

What changes are included in this PR?

A custom printer was added for the test case. I believe the sanitizer error was occurring because the bytes of the std::vector were being printed (and may not have been initialized yet).

Are these changes tested?

Yes

Are there any user-facing changes?

No!

• GitHub Issue: [C++][Parquet] test-conda-cpp-valgrind fails on parquet tests #46314

[github-actions]

⚠️ GitHub issue #46314 has been automatically assigned in GitHub to PR creator.

[paleolimbot]

@github-actions crossbow submit test-conda-cpp-valgrind

[github-actions]

Revision: c295bd5

Submitted crossbow builds: ursacomputing/crossbow @ actions-ced901251e

Task	Status
test-conda-cpp-valgrind

[paleolimbot]

@github-actions crossbow submit test-conda-cpp-valgrind

[github-actions]

Revision: ff7c450

Submitted crossbow builds: ursacomputing/crossbow @ actions-7cd4146254

Task	Status
test-conda-cpp-valgrind

[paleolimbot]

It looks like there are other valgrind failures here...I will take a closer look tomorrow, but I think this fixes that particular issue!

[wgtmac]

Thanks!

[conbench-apache-arrow]

After merging your PR, Conbench analyzed the 4 benchmarking runs that have been run so far on merge-commit f25fab4.

There were no benchmark performance regressions. 🎉

The full Conbench report has more details. It also includes information about 11 possible false positives for unstable benchmarks that are known to sometimes produce them.