Add support for sony store

Add support to find prices at the sony store.  Because this store uses
javascript heavily, we must instead rely on their API (so no page
scrape).  So if the URI is for the sony store, perform separate logic
than page scraping to obtain the price, category, and name.
Display subcategory if we have it: add tracked item page

If we've received the subcategory from the server, display it in the UI
before adding the tracked item.