ROS1 nodes - None argument fix (#306)

* Pose est: Added lambda expression in argparse to handle passing of none value and minor optimization

* Face reco: Added lambda expression in argparse to handle passing of none value

* Fall det: Added lambda expression in argparse to handle passing of none value and some fixes in callback

* Fixed whole fall detection list being published for each fallen pose

* Fallen message now publishes only when there is a fall detected

* Each fallen pose now has different id

* Face det: Added lambda expression in argparse to handle passing of none value and minor optimization

* Obj det 2d: Added lambda expression in argparse to handle passing of none value and minor optimization

* Sem segm: Added lambda expression in argparse to handle passing of none value

* Moved pose bounding box calculation inside if block