Compendia Download Events Script

### Context

We want to track compendium download events.

### Problem or idea

We should write a script that queries aws to get a human readable outputs a tsv like:

| Organism Name | Downloads | Users |
| ------------- |:-------------:| -----:|
| HOMO_SAPIENS | 4 | 4 |
| MUS_MUSCULUS | 2 | 1 |
| DANIO_RERIO | 1 | 1 |

### Solution or next step

Write a command that queries and aggregates these values.

The issue names no file, test, or command entry point, so first locate existing compendium download-event handling and AWS query patterns. The work is done when a command queries AWS, aggregates downloads and users by organism, and emits the requested human-readable TSV.

Written by the indexing model from the issue text.