Implement `evaluate` logic for multiple incomplete instances of the same ability

[howlowck]

Description: Before the logic for evaluate is to simply look for the incomplete ability in the WolfState. Now there needs to be new logic for wolf (or the user) to determine which instance of the incomplete ability should wolf strive for completion first.

Acceptance Criteria:

• Wolf's evaluate stages finds the best ability to strive for completion ... through least slot-to-fill for completion
• through FIFO if slot-to-fill is the same for all instances of the incomplete ability
• ... through user-defined function