Beta Plugin: Use foldable card to display changelog beneath each available version

Currently we see this:


Ideally we would use a foldable card for those entries and when expanded we could display the changelog or perhaps a list of merged PRs (not sure what's possible there).

cc @enejb @samhotchkiss

The issue names no files or tests; start by locating the UI entry point that renders available plugin versions. Determine whether changelogs or merged PRs are available, then verify that each version can expand to show the selected details.

Written by the indexing model from the issue text.