Resolve missing config file

[FaresKchaou]

summary

Following #25 and PR #27, this PR is created and is based on #27.

In #27, the config file was added as a parameter, which is no longer optional. However, the intended idea was to make this parameter optional so that users configuring with the ifmVision Assistant or pure API are not required to reconfigure. They can simply publish the point clouds and ODS data without additional steps.

Additional Changes (form #27):

• add missing declare_parameter for the config_file parameter in ods_node.cpp
• Change RCLCPP_INFO to RCLCPP_DEBUG for logging the configuration contents in camera_node.cpp and ods_node.cpp because this produces a lot of output.