This pull request is to separate Gen3 Lite MoveIt2 planning groups between the arm and gripper to allow for easier usage.
This pr addresses issue 249.

Created different MoveIt2 motion planning groups to separate arm and gripper planning.
Created saved group_states for arm:vertical, arm:home, gripper:open, and gripper:closed like ros1.
The new planning group requires the additional gripper group in kinematics.yaml.
Since both groups use the joint_trajectory_controller, the allow_partial_joint_goals parameter needs to be true in ros2_controllers.yaml to allow them to move independently.
Tested with:

ros2 launch kortex_bringup kortex_sim_control.launch.py sim_ignition:=false sim_gazebo:=true robot_type:=gen3_lite robot_name:=gen3_lite dof:=6 gripper:=gen3_lite_2f launch_rviz:=false

ros2 launch kinova_gen3_lite_moveit_config sim.launch.py