HTML frontend

[mikepurvis]

It would be great if colcon_distro_server had a browsable web interface, perhaps at a bare minimum providing some summary-type information like about the number of snapshots stored and the space used, perhaps also links to the most recently-created snapshots. If those had subpages, it would be great to be able to be able to do some simple querying stuff, like "find this package", "list all run/build-depends of this package", etc. Potentially could leverage a tool like jq for an agnostic querying interface.

More complex, it would be neat to be able to do cross-snapshot queries, like "show me when this repo/package last changed", or "show me the deltas between these two snapshots."

Hopefully all or most of this could be implemented entirely in static assets, just fetching the JSON from the API endpoints and rendering it into templates client-side.