Fixing two compile issues (on Ubuntu 22.04 running ROS2 Humble)
avoid missing type errors in "this->declare_parameter" functions in the initialisation section of the file 'rplidar_scan_publisher.cpp' by combining 'get_parameter_or' into the 'declare_parameter' section.
fixed "narrowing conversion of 'rp::hal::Event::EVENT_TIMEOUT' from 'int' to 'long unsigned int'" error messages by type-casting to an 'int'
Fixing two compile issues (on Ubuntu 22.04 running ROS2 Humble)