Data obfuscation layer for encryption

Data obfuscation in sensitive columns - for users without access to column encryption keys.
1. Implement on top of [basic Parquet encryption](https://github.com/apache/parquet-format/blob/encryption/Encryption.md) 
1. Built-in support for multiple masking mechanisms, with different trade-off between data utility, leakage, and size/throughput overhead
1. Provide interface for plug-in custom masking mechanism
1. Enable storing multiple masked versions of the same column in a file
1. Provide readers with explicit list of column’s masked versions in a file
1. Enable readers to select a masked version of a column
1. Stretch: Implement tools for analysis of file data privacy properties and information leakage
1. Stretch: Leverage privacy analysis tools for tuning file data anonymity
1. Optional: Support aggregated obfuscation

**Reporter**: [Gidon Gershinsky](https://issues.apache.org/jira/secure/ViewProfile.jspa?name=gershinsky) / @ggershinsky
**Assignee**: [Gidon Gershinsky](https://issues.apache.org/jira/secure/ViewProfile.jspa?name=gershinsky) / @ggershinsky
#### Related issues:
- [Parquet modular encryption](https://github.com/apache/parquet-java/issues/2110) (depends upon)
#### PRs and other links:
- [discussion googledoc](https://docs.google.com/document/d/1LMs74uhqvMNJacBySPnWq6tM8qIpgcIZz444c7vfibM/edit?usp=sharing)

_{**Note**: *This issue was originally created as [PARQUET-1376](https://issues.apache.org/jira/browse/PARQUET-1376). Please see the [migration documentation](https://issues.apache.org/jira/browse/PARQUET-2502) for further details.*}

Start by reading the linked Parquet basic encryption specification and the related modular encryption issue, then review the linked discussion document. The issue describes masking mechanisms, plug-in support, multiple masked column versions, reader selection, and optional analysis tools, but names no Java files or tests; done would require agreeing on and implementing that broad design.

Written by the indexing model from the issue text.