Replace file download lists with counts in static analytics pages

[MillenniumFalconMechanic]

Summary

The static analytics pages for HCA, AnVIL Explorer, and LungMAP currently display individual file names in the file downloads tables. These should be replaced with aggregate counts only.

Current Behavior

There are two file download tables rendered in the static analytics pages:

1. "Direct File Downloads" — shows individual file names (entity_name), associated dataset names (related_entity_name) with links, and download counts
2. "File Download Events" (under Resources) — shows individual file paths (file_name) and download counts

Both tables list specific file names/paths.

Desired Behavior

Replace both file download tables with simple aggregate counts (total number of file download events). No individual file names or paths should be displayed.

Files to Modify

• analytics/analytics_package/analytics/static_site/template/index.html — remove file download table rendering, replace with count display
• analytics/analytics_package/analytics/static_site/fetch.py — simplify get_file_downloads() and get_file_download_events() to return counts only
• analytics/analytics_package/analytics/static_site/export.py — update export to write counts instead of file lists