Expose wakeUp() in body api

[andreivips]

Hi, and thanks for great libs !

Bodies falls asleep ( when <Physics allowSleep={true}> ), but after, won't move with applyImpulse/Force, wakeUp() needs to exposed:
https://github.com/pmndrs/cannon-es/blob/eb222d1169195dd0b570d1aaa749a814bacd747a/src/objects/Body.ts#L261

Also, cannons world.hasActiveBodies is used to invalidateFrameloop in react-three-fiber:

use-cannon/src/Provider.tsx

Line 151 in 0243fb3

if (e.data.active) invalidate()

and can be exposed in useCannon's Provider (<Physics...>) to track bodies state.

Maybe with an iteration few more methods/props would be straight available.

[johnmarinelli]

i also ran into this issue, would be nice to have this feature

[andreivips]

Should be closed by pmndrs/cannon-es#61