Allow for a relative robot namespace. Instead of causing an error, it will use the node namespace as a parent to fully qualify the robot namespace. This is desirable for Turtlebot4 because the namespace is pushed in a parent launch file relative to where the republisher is launched (launch file).
Added 3 more topics to be enabled by default - if you disagree with this then I can put a copy of this params.yaml in the Turtlebot4 Robot package that launches the republisher. These topics are required for base Turtlebot4 functionality.