R1:6df1a024137c

(Redesign) Clean up older "Tile" code

Summary:
This does some backend cleanup of the tile stuff, and some general cleanup of other application things:

- Users who haven't customized preferences get a small, specific set of pinned applications: Differential, Maniphest, Diffusion, Audit, Phriction, Projects (and, for administrators, Auth, Config and People).
- Old tile size methods are replaced with `isPinnnedByDefault()`.
- Shortened some short descriptions.
- `shouldAppearInLaunchView()` replaced…