Feature: track repair time in Tankopedia

Adds track repair time to the Tankopedia survivability stats, matching the value the game lists.

- Added a required `repair_time` to track definitions, filled from each chassis's hysteresis health divided by its health regen per second
- Applied the toolbox, the repair crew skill and the protective kit as multiplicative repair speed bonuses
- Added a Track repair time row under fire chance; it appears once the definitions are regenerated on the next build

Fixes #308

packages/i18n/strings/en.json

@@ -683,6 +683,7 @@
             "hullTraverseSoftTerrain": "Soft",
             "health": "Health",
             "fireChance": "Fire chance",
+            "trackRepairTime": "Track repair time",
             "viewRange": "View range",
             "camouflageStill": "Camouflage still",
             "camouflageMoving": "Moving",