Add integration with ItemBridge

[knokko]

The plug-in ItemBridge (see https://polymart.org/resource/item-bridge.4 ) seems interesting because:

• It could help me with making my recipe editor more powerful (the types of ingredients are currently quite limited and copied to server results are suboptimal as well).
• Adding integration with more plug-ins will be easier once more plug-ins start using ItemBridge. Even though little plug-ins support it at the moment, this might change in the future, and joining early could contribute a bit to this.

[knokko]

Custom Items 9.14 will have partial ItemBridge support: it will register its items to ItemBridge, but it won't be able to use ItemBridge items that are registered by other plug-ins in its custom recipes.