Expose impulse joint motor max force

[zdtango]

Summary

Expose setMotorMaxForce(maxForce) on UnitImpulseJoint for JavaScript users.

Rapier core already exposes this through set_motor_max_force, but the JS/WASM wrapper currently exposes motor model/velocity/position configuration without exposing the separate max-force setter.

Why

This lets JS users cap solver-level joint motor force/torque directly instead of approximating motor force limits outside the joint solver. It is useful for cases like vehicle wheel motors, brakes, doors, and robotics where motor targets need a finite force limit.

Changes

• Add RawImpulseJointSet.jointSetMotorMaxForce(...) in the wasm binding layer.
• Add UnitImpulseJoint.setMotorMaxForce(maxForce) in the TypeScript wrapper.

Validation

• cargo check -p dimforge_rapier3d
• cargo fmt --check -- src/dynamics/impulse_joint.rs
• npx prettier --check src.ts/dynamics/impulse_joint.ts

[sebcrozet]

Thanks!