handle gripping case

[timtmit]

This pull request introduces enhancements to the OnRobotGripper class to improve the detection of gripper movement completion, including handling scenarios where the gripper stalls

Enhancements to movement detection:

• Added new variables for movement tracking: Introduced _last_known_position and _last_position_change_time to track the gripper's position and the last time it changed significantly (onrobot_gripper.hpp).
• Updated movement initialization: Reset _last_known_position and _last_position_change_time when a new command is issued to ensure accurate tracking (onrobot_gripper.cpp).

Improvements to gripper movement logic:

• Refined movement completion conditions: Enhanced the logic to determine when the gripper has finished moving, including:
  • Checking if the target position is reached within a tolerance of 2%.
  • Detecting if the gripper has stalled by monitoring position changes and timing out after 5 seconds of inactivity (onrobot_gripper.cpp).
• Reset command state appropriately: Ensured the _command_in_progress flag is reset only when movement is confirmed as finished, either by reaching the target position or due to stalling (onrobot_gripper.cpp).