Feature/safety position controller

[Joschi3]

This PR introduces the SafetyPositionController, a chainable ROS 2 controller that ensures safe joint position commands.

Key features

• Unwraps continuous joints to avoid 2π jumps
  • Assumes HardwareInterface expects joint commands in (-inf, inf) [example Gazebo]
• Enforces joint limits based on URDF definitions
• Operates only in chained mode (no direct subscribers)
• Exports reference interfaces (safety_position_controller//position) for use by upstream controllers (e.g., trajectory controller)