Deep verification of encrypted files

A tools that verifies encryption of parquet files in a given folder. Analyzes the footer, and then every module (page headers, pages, column indexes, bloom filters) - making sure they are encrypted (in relevant columns). Potentially checking the encryption keys.

We'll start with a design doc, open for discussion.

**Reporter**: [Gidon Gershinsky](https://issues.apache.org/jira/secure/ViewProfile.jspa?name=gershinsky) / @ggershinsky
**Assignee**: [Maya Anderson](https://issues.apache.org/jira/secure/ViewProfile.jspa?name=mayaa) / @andersonm-ibm
#### PRs and other links:
- [Design doc](https://docs.google.com/document/d/1c6Vc2X2CPTReWG3aHoBhOBUJ7ghk80wTzcqs04bBDX8/edit?usp=sharing)

_{**Note**: *This issue was originally created as [PARQUET-1989](https://issues.apache.org/jira/browse/PARQUET-1989). Please see the [migration documentation](https://issues.apache.org/jira/browse/PARQUET-2502) for further details.*}

Start with the linked design document, since the issue proposes beginning with design discussion and names no source files or tests. Define the verifier's scope and acceptance criteria for checking encrypted Parquet footers, modules, relevant columns, and potentially keys; done means the design is agreed before implementation begins.

Written by the indexing model from the issue text.