Inventory and container tooltip fixes

Fixed

• Fixed /give silently losing intentionally non-stackable items such as tools and shulker boxes
• Fixed container and shulker-box tooltips displaying 64 instead of the exact contained stack count
• Preserved item types in zero-count copies used by vanilla inventory insertion
• Prevented inventory insertion from mutating Minecraft's shared empty-stack singleton
• Preserved signed 64-bit counts when displaying container contents

Important

• The mod must be installed on both the client and server
• Worlds containing oversized stacks depend on this mod
• Back up your worlds before installing or updating
• Compatibility with every mod is not guaranteed