Promote ConfigFileName to a standalone struct with per-call-site cons…

…tants

Replace the nested `FileName` enum on `HolodeckConfigResolver` with a
top-level `ConfigFileName` struct, and move the `config.json` and
`url-history.json` constants next to the stores that use them.

Filter Apple TV device types out of the create-wizard catalog

Move shared view helpers, hoist enum labels, simplify privacy wizard