Fix/ros2 build param issues

[Alpaca-zip]

Thank you for your great project!
I have found some problems in using your ROS 2 package and have made a PR about the fixes.

PR Type

• Feature
• Bug fix
• Refactor
• Documentation
• Other

Overview

• Fixes problems with colcon build not going through.
• Fixes problems with access to parameters.
• Delete unused parameter.

Detail

• In pcl_ros for ROS 2, pcl_ros/point_cloud.h is incorrect and the correct name is pcl_ros/point_cloud.hpp. However, as mentioned below, pcl_ros/point_cloud.hpp is not yet implemented and the build will not pass. For this issue, only commenting it out improved it and did not interfere with its functioning.
  ROS2 Port ros-perception/perception_pcl#225 (comment)
• As mentioned below, ROS 2 Dashing or later requires that a declaration is made before parameters can be accessed. Therefore, I added declarations for r_min, r_max and max_fit_error, which had not been declared.
  https://docs.ros.org/en/galactic/Releases/Release-Dashing-Diademata.html#declaring-parameters:~:text=As%20of%20Dashing%2C%20parameters%20now%20need%20to%20be%20declared%20before%20being%20accessed%20or%20set.
• The parameter latch has been removed as it is not used in this code.

Test

• I have tested this change with gazebo.

[baiyeweiguang]

Thank you for your PR! I'm not familiar with pcl-ros, so I'm not sure what role pcl-ros/point_cloud.h plays in the code.