brick detection using laser scan in 2D manner

[tongtybj]

Add launch file using https://github.com/tongtybj/aerial_robot_recognition/pull/27 .

$ roslaunch mbzirc2020_task2_common bringup.launch simulation:=true real_machine:=false headless:=false
$ roslaunch mbzirc2020_task2_tasks horizontal_brick_detection.launch

In gazebo, move the hydrus using GUI, also change the joint angles (e.g. 0.8 rad).
Then in rviz, subscribe the topic object_markers, then you can get result as follows: