fix memory issues in btSparseSDF.h

(hash function on structure with uninitialized padding, and  Reset not called in destructor)
expose sparseSdfVoxelSize in PyBullet.setPhysicsEngineParameter
don't call deformable wireframe drawing in the wrong thread/place (it can cause crashes)

examples/SharedMemory/SharedMemoryCommands.h

@@ -484,6 +484,7 @@ enum EnumSimParamUpdateFlags
 	SIM_PARAM_REPORT_CONSTRAINT_SOLVER_ANALYTICS = 1 << 26,
 	SIM_PARAM_UPDATE_WARM_STARTING_FACTOR = 1 << 27,
 	SIM_PARAM_UPDATE_ARTICULATED_WARM_STARTING_FACTOR = 1 << 28,
+	SIM_PARAM_UPDATE_SPARSE_SDF = 1 << 29,
         
 };