- Velocity control implemented with functions for velocity commands -> requires add-on (Velocity or Motion)!
- Velocity control possible in joint space (JOINT) or cartesian space (w.r.t. BASE/TOOL frame)
- Velocity control mode is started with a VelocityConfig message with various parameters (e.g. vel/accel limits)
- Added state machine to switch between motion control modes (JOINT_TRAJECTORY_STREAMING, VELOCITY_CONTROL)
  -> the default mode is JOINT_TRAJECTORY_STREAMING and works as before
- Increased feedback task frequency (synced with interpolation clock)
- SYSTEM socket interface (receiver task, port 11001) to handle system commands (e.g. set drive power)
- IO socket interface (receiver task, port 11003) to handle IO commands (e.g. read/write IO)
  -> only writing single IO is fully implemented

Other changes/improvements:

- Sending JointFeedback message including joint velocities -> requires add-on (Motion)!
  Note: The generic industrial_robot_client doesn't support JointFeedback messages
- Renamed socket name "Feedback" -> "State" (socket configuration must be adapted on the controller!)
- Used VAL3 libraries and custom types for better modularization
- Used VAL3 custom types for "enums"
- Added debug screen for debug messages (switching to the debug screen activates the "debug mode")

- robot_state node with additional support for JointFeedback messages
- IO interface for reading/writing IO (only "write single IO" fully implemented)
- system interface for system commands ("set drive power" implemented)
- added staubli_msgs package (with IO related messages/services)