Allow the Magnet Upgrade to be installed in the Pneumatic Helmet, and draw items toward the player.

• Would have a (very small) air cost when pulling items.
• Default range could be 4-6 blocks? Allow stacked Magnet Upgrades to increase that to maybe 12-16 blocks?
• Should respect the Botania Solegnolia.
• Should be toggleable in the helmet GUI, and allow a hotkey to be assigned to toggle it.
• Could possibly support item filtering in the helmet GUI; whitelist/blacklist of up to 9(?) items with possible meta/NBT/oredict support. Not a high priority, could be considered an advanced feature.

This is getting included in #21.