Overhaul and Improve AI_FLAG_STALL

[pkmnsnfrn]

Description

Similar to how AI_FLAG_SETUP_FIRST_TURN and AI_RISKY are being merged together, the same should happen to AI_FLAG_CONSERVATIVE and AI_FLAG_STALL once AI_FLAG_STALL is improved.

Discord contact info

Pawkkie

[Pawkkie]

This was initially pitched as merging the Conservative behaviour into the Stall flag to coincide with an overhaul improving and expanding Stall's behaviour in much the same way we did recently for Risky.

Based on the Battle AI poll feedback and some discussion with Alex, we've decided we think it'd be best to maintain Conservative as its own separate flag in addition to the Stall overhaul, hence this issue being retitled :)