Group World Behaviors into their own folder

[Psypher9]

There are a few assets of background behaviors of the world for non-player objects, for instance: mobs, items, rooms, and areas.

These behaviors should be grouped together for better organization. Perhaps a behaviors

Behaviors Key Files:

• Mob Behaviors - mprog
• Item Behaviors - iprog
• Room Behaviors - rprog
• Area Behaviors - aprog

There are several enums in merc.h that belong in behaviors as well:

• MPROG Actions - merc.h#L329-L340
• IPROG Actions - merc.h#L346-L363
• RPROG Actions merc.h#L369-L374
• APROG Actions merc.h#L369-L374

[Psypher9]

There are a few other things I'm seeing in merc.h called affects that seem to be related to these and it might make sense to move those into a behaviors/affects directory eventually