feat: add ITEM_FIELD_DURABILITY/MAXDURABILITY to all expansion update_fields

- Classic/Turtle: indices 48/49 (no spell-charge fields between stack
  count and durability in 1.12)
- TBC: indices 60/61 (same layout as WotLK, matches TBC 2.4.3 item fields)
- WotLK: already added in previous commit

Enables durability tracking across all supported expansion profiles.

Data/expansions/classic/update_fields.json

@@ -34,6 +34,8 @@
   "PLAYER_END": 1282,
   "GAMEOBJECT_DISPLAYID": 8,
   "ITEM_FIELD_STACK_COUNT": 14,
+  "ITEM_FIELD_DURABILITY": 48,
+  "ITEM_FIELD_MAXDURABILITY": 49,
   "CONTAINER_FIELD_NUM_SLOTS": 48,
   "CONTAINER_FIELD_SLOT_1": 50
 }

Data/expansions/tbc/update_fields.json

@@ -33,6 +33,8 @@
   "PLAYER_EXPLORED_ZONES_START": 1312,
   "GAMEOBJECT_DISPLAYID": 8,
   "ITEM_FIELD_STACK_COUNT": 14,
+  "ITEM_FIELD_DURABILITY": 60,
+  "ITEM_FIELD_MAXDURABILITY": 61,
   "CONTAINER_FIELD_NUM_SLOTS": 64,
   "CONTAINER_FIELD_SLOT_1": 66
 }

Data/expansions/turtle/update_fields.json

@@ -34,6 +34,8 @@
   "PLAYER_END": 1282,
   "GAMEOBJECT_DISPLAYID": 8,
   "ITEM_FIELD_STACK_COUNT": 14,
+  "ITEM_FIELD_DURABILITY": 48,
+  "ITEM_FIELD_MAXDURABILITY": 49,
   "CONTAINER_FIELD_NUM_SLOTS": 48,
   "CONTAINER_FIELD_SLOT_1": 50
 }