Change editorial brand names to provide better defaults and to prevent current and future string collisions (bug 1055851)

New approach:

- Change the strings to prevent collisions.
- Move editorial brand names to its own file. Yes, it does create another file we have to keep in sync between fireplace and transonic, but this one should almost never change. It's worth it to prevent accidental changes.

r? @clouserw @ngokevin
`get_brand_type('apps-for-canada', 2)` is a better example :grin: