Allow rendering RSVP locations as `h-card`s or `h-adr`s

As noted in 8b48459c and www-api#150, the format of events the site is expecting weren't full h-card or h-adrs, which then broke the site's rendering.

Some files have changed a fair bit due to the pretty-printing formats being different between Ruby (how we're writing these files) vs Java (how they were mostly originally written).

This need change only in the way that the site renders, as events now being submitted as a valid h-adr or h-card will be passed through without inspecting.