ParquetOutputCommitter should propagate errors when writing metadata files

There's a lot of different ways the output committer can fail, or fail to rollback after failing to write metadata files. We should decide whether metadata files are required, and fatal (I think that's reasonable if the user asked for them), and propagate without squashing exceptions.

**Reporter**: [Alex Levenson](https://issues.apache.org/jira/secure/ViewProfile.jspa?name=alexlevenson) / @isnotinvain
#### PRs and other links:
- [GitHub Pull Request #502](https://github.com/apache/parquet-mr/pull/502)

_{**Note**: *This issue was originally created as [PARQUET-383](https://issues.apache.org/jira/browse/PARQUET-383). Please see the [migration documentation](https://issues.apache.org/jira/browse/PARQUET-2502) for further details.*}

Start with ParquetOutputCommitter and review the linked pull request #502, along with the original PARQUET-383 context. Clarify whether metadata-writing failures are fatal and how rollback errors should be propagated; done means the chosen behavior is implemented without squashing the relevant exceptions and is covered by tests.

Written by the indexing model from the issue text.