Item swapping and restraint system upgrade

Added a new mechanic where players can bring equipment into battle and swap between them. The equipment grid can be viewed by pressing the ADJUST_EQUIP key and pressing ADJUST_EQUIP key + a DIRECTIONAL key will swap to that piece of equipment.

With certain equipment equipped, characters can now get an additional grab option when grabbing an opponent. So for example, with blind fold equipped, the character gets an option to put that blind fold onto the opponent. Restraint grabs used this way ignores cooldowns and the durability of restraint is higher than the original restraint grabs (100 durability versus 50). This restraint durability, among other things, can be set on a per equipment basis so its possible to have tiered restraint equipment with progressively stronger effects.

This is how it looks like in action: