Latched topic instead of continuously looped

[horverno]

Instead of 40 HZ (ros::Rate rate(40);) a latched topic.

Quote from ROS documentation:

latch [optional] - Enables "latching" on a connection. When a connection is latched, the last message published is saved and automatically sent to any future subscribers that connect. This is useful for slow-changing to static data like a map. Note that if there are multiple publishers on the same topic, instantiated in the same node, then only the last published message from that node will be sent, as opposed to the last published message from each publisher on that single topic.