Add personal characteristics to each AI agent

[AndyTechGuy]

With the factions system introduced in #36, each character in an individual city shares a common character model. This can make the citizens look rather plain in a group, therefore some distinguishing characteristics should be included in the spawn process, like below:

• A name for each citizen, like what is already done for cities. Randomized physical NPC traits #74
• Variations in character size, easily done with the scale property inside the skeletalmesh of a character prefab. Randomized physical NPC traits #74
• Personality traits for each character which manipulate some behaviors, for example a lazy character would move slower, a greedy character would get hungry faster, etc.
• Slight colour/tone variations between characters. Attempted as part of Randomized physical NPC traits #74, didn't look good.

[jdrueckert]

@AndyTechGuy Guess after your second year of GSoC that's been resolved? 😁