Wait set uses pointers to rcl types not rcl->impl types (#324)
Wait set uses pointers to rcl types not rcl->impl types (#324)

* WAITSETBUG: Get ready entities by rcl type

Signed-off-by: Shane Loretz <7fde345e8e2e22c78a1570a4807e4629866dc7de@osrfoundation.org>

* Create pointer to gc not gc->impl

Signed-off-by: Shane Loretz <7fde345e8e2e22c78a1570a4807e4629866dc7de@osrfoundation.org>

* pygc_impl_reference -> pygc_reference

Signed-off-by: Shane Loretz <7fde345e8e2e22c78a1570a4807e4629866dc7de@osrfoundation.org>

ros2/rclpy,ros2/rclpy