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GH-42102: [C++][Parquet] Add binary that extracts a footer from a parquet file (#42174)

### Rationale for this change

This binary will make it a lot easier for customers to share their parquet metadata with the community so that we can build a repository of footers that can be used for advancing the state of metadata in parquet.

### What changes are included in this PR?

Usage from the file binary itself:
```
Usage: parquet-dump-footer
  -h|--help    Print help and exit
  --no-scrub   Do not scrub potentially confidential metadata
  --debug      Output text represenation of footer for inspection
  --in <uri>   Input file (required): must be an URI or an absolute local path
  --out <path> Output file (optional, default stdout)

  Dump the footer of a Parquet file to stdout or to a file, optionally with
  potentially confidential metadata scrubbed.
```

### Are these changes tested?

Manually on existing parquet files.

### Are there any user-facing changes?

No.

* GitHub Issue: #42102

Lead-authored-by: Alkis Evlogimenos <alkis.evlogimenos@databricks.com>
Co-authored-by: Antoine Pitrou <antoine@python.org>
Signed-off-by: Antoine Pitrou <antoine@python.org>