Performance improvement for static or sleeping bodies.

[eyeseet]

Loop only non-static/non-sleeping bodies 8 times instead of all bodies. At the cost of one extra loop in Engine.update. Estimate is improved performance when >12% of bodies is sleeping or static.

[eyeseet]

From what I understand from the documentation https://brm.io/matter-js/docs/classes/Body.html#property_isSleeping static bodies can be threaded as if sleeping and vice versa. In this case further optimizations are possible such as:

• Sleeping.update function.
• Only one array to track either sleeping or static bodies (instead of one for each) in Engine.update.
• Also several check in the loops of the methods that get bodies passed as parameter can be improved.