Develop stabilize_at_position Action

[charlesmadjeri]

Description:

Implement the /stabilize_at_position action to continuously stabilize the USV in a specific position.

Tasks:

• Create service definition for stabilize_at_position, taking wanted position (and optionnal orientation) input and a stabilization status feedback (stabilizing, stabilized)
• Implement logic to maintain null velocity except for position stabilization movements
• Provide feedback on stabilization status