Traveler's Backpack Functionality Upgrades

Upgrades are special modules that can be slotted into the backpack to provide automated features.

• Crafting Upgrade: Adds a 3x3 crafting grid to the backpack GUI.
• Tank Upgrade: Adds two additional fluid tanks for extra storage.
• Feeding Upgrade: Automatically feeds the player using food stored in the backpack.
• Magnet Upgrade: Pulls nearby items directly into the backpack inventory.
• Pickup Upgrade: Automatically places items picked up from the ground into the backpack.
• Void Upgrade: Deletes specific filtered items automatically.
• Refill Upgrade: Automatically refills items (like blocks or torches) from the backpack into the player's hotbar.
• Furnace/Smoker/Blast Furnace: Allows smelting items directly inside the backpack.
• Jukebox Upgrade: Allows playing music discs while traveling.
• Lantern Upgrade: Provides light around the player (requires LambDynamicLights mod).