chore: remove DotcomWeb.Components.Prototype

[thecristen]

Scope

Asana Ticket: 📅🔎🚀 | QF | Pre-release, remove the testing route/direction/stop selector from the top

Implementation

Removed the component, then realized we don't need the handle_params/3 callback, as that's useful when navigating within a LiveView.

• Instead, we can do all of our data loading in mount/3. So I did this refactor, which let me remove some of the smaller intermediate functions like assign_route/2 or assign_stop/2.
• I also tweaked the "go to 404" handling slightly to handle this in the mount/3 as well. Turns out you can raise an exception.
• I removed a few :if={@stop} from the template, since by the time we render we've already fetched the stop.

The diff looks more dramatic than it actually is, because nothing else was changed here...

Screenshots

It looks the same, but without the buttons for switching any of the URL params.

How to test

Manually try different URLs 😩

• /departures should redirect to /schedules
• /departures with a combination of URL params that doesn't have a valid route_id, direction_id or stop_id will return the 404 page

[joshlarson]

Goodbye Prototype Picker! It was a good run 🥲