Rewrite mimic joints

[christophfroehlich]

The component_parser of the resource_manager now already parses the mimic joint information from the URDF. The old way for defining it in the ros2_control tag is deprecated, see ros-controls/ros2_control#1256.

If this one is approved, I'll make the same changes for gz_ros2_control as well.

• This PR uses the info from the hardware_info structure instead of parsing it again.
• From my understanding, mimic means "mimic position", but the URDF spec is not very clear in this point. So I implemented it that independently of the interface type of the mimicked joint, the mimic joint's position is set. See also Add doc page about joint kinematics ros2_control#1497 for the discussion.
• replaces Mimic joints independent of the combination of command interfaces #111
• fixes "_mimic" joint interface name suffix causes Moveit2 "Joint not found" Error #173 (remove suffix _mimic):

$ ros2 control list_hardware_interfaces
command interfaces
        right_finger_joint/position [available] [claimed]
state interfaces
        left_finger_joint/effort
        left_finger_joint/position
        left_finger_joint/velocity
        right_finger_joint/effort
        right_finger_joint/position
        right_finger_joint/velocity

[saikishor]

The PR overall looks good to me. Thanks for the changes. I left few comments for clarification

[saikishor]

LGTM. Thank you for the changes :)

[ahcorde]

Tested locally, LGTM, just two minor comments