Refactor AICharacter(s) to use the GAS-like Action sytem

[rolandsarosy]

Since they GAS-like Action system was written later than the AI logic was, the AICharacters are not compatible with this system.

That means, they don't use Actions to move, see, seek, spawn projectiles, heal, etc.

This refactor would essentially mean to rewrite the BTTasks and BT behaviors to make them compatible with my GAS implementation.