[BREAKING] Item Usage Overhaul

-De-hardcode elemental orb values
-De-hardcode exp items
-Change ShopChest format (temporary, drop system overhaul will replace it entirely)
-Food healing actually uses Ability data for real HP amounts

src/main/java/emu/grasscutter/game/props/ItemUseAction/ItemUseGainAvatar.java

@@ -0,0 +1,43 @@
+package emu.grasscutter.game.props.ItemUseAction;
+
+import emu.grasscutter.game.avatar.Avatar;
+import emu.grasscutter.game.props.ItemUseOp;
+import emu.grasscutter.game.systems.InventorySystem;
+
+public class ItemUseGainAvatar extends ItemUseInt {
+    private int level = 1;
+    private int constellation = 0;
+
+    @Override
+    public ItemUseOp getItemUseOp() {
+        return ItemUseOp.ITEM_USE_GAIN_AVATAR;
+    }
+
+    public ItemUseGainAvatar(String[] useParam) {
+        super(useParam);
+        try {
+            this.level = Integer.parseInt(useParam[1]);
+        } catch (NumberFormatException ignored) {}
+        try {
+            this.constellation = Integer.parseInt(useParam[2]);
+        } catch (NumberFormatException ignored) {}
+    }
+
+    @Override
+    public boolean useItem(UseItemParams params) {
+        int haveConstellation = InventorySystem.checkPlayerAvatarConstellationLevel(params.player, this.i);
+        if (haveConstellation == -2 || haveConstellation >= 6) {
+            return false;
+        } else if (haveConstellation == -1) {
+            var avatar = new Avatar(this.i);
+            avatar.setLevel(this.level);
+            avatar.forceConstellationLevel(this.constellation);
+            avatar.recalcStats();
+            params.player.addAvatar(avatar);
+            return true;
+        } else {
+            int itemId = (this.i % 1000) + 100;
+            return params.player.getInventory().addItem(itemId);
+        }
+    }
+}