Make writeAllFields more efficient in proto-parquet component

This will improve the write performance by 1/3 - 1/4 based on my testing. It makes a huge difference when dealing with really large files (several GBs).

In the original implementation, a significant time was spent on creating unnecessary Java objects.

**Reporter**: [Chen Song](https://issues.apache.org/jira/secure/ViewProfile.jspa?name=capricornius)
**Assignee**: [Chen Song](https://issues.apache.org/jira/secure/ViewProfile.jspa?name=capricornius)

_{**Note**: *This issue was originally created as [PARQUET-535](https://issues.apache.org/jira/browse/PARQUET-535). Please see the [migration documentation](https://issues.apache.org/jira/browse/PARQUET-2502) for further details.*}

Start by locating writeAllFields in the proto-parquet component and reviewing its current object-creation path. Use the issue's large-file performance scenario as the benchmark; done means the method avoids the unnecessary Java objects identified in the implementation and shows the intended write-performance improvement.

Written by the indexing model from the issue text.