Statistics Extended

Adds a "Statistics Extended" tab to the in-game Statistics screen with two lists for your active savegame:

- Achievements: name, description, and progress (or "Unlocked") for every achievement registered by the game. Note: some unlock condition descriptions are best-effort guesses, not official text.
- Farm Statistics: session and all-time totals covering breeding, distances traveled, field area worked, time spent on tasks, resource usage, harvests, bales, wood, and more. A few of these duplicate values already shown on the vanilla Statistics tab.