ROS2: Improvements for OpenRB-150, Franka Gello Duo and reliability

[AndreasJosefGassner]

This PR provides improvements to the ROS2 part of the repository:

• Adaptions for OpenRB-150 support as an alternative to the U2D2 converter.
• Virtual springs and dampers are disabled by default, as using torque with the OpenRB-150 board without an external power supply may damage the user's USB port according to the board's documentation. A warning has been added indicating that external power must be provided before enabling these features.
• Added a configuration file for the pre-assembled Franka Gello Duo.
• Renamed example config files and updated the default config file used by franka_gello_state_publisher accordingly.
• Improved Dynamixel initialization reliability by starting joint-position polling only after initialization is complete.