wip1
Refactor|PlayerImpulse: Separate Impulse, PlayerImpulse and ImpulseAccumulator components

PlayerImpulse is Record-like (todo) description of a logical player
impulse. Each local player has their own set of ImpulseAccumulators,
which, accumulate and normalize multiple impulse triggers ready for
later rationalize by the player's Brain (on game side).