Unused header cleanup (backport #1199)

[mergify]

This PR just removes unused headers, replacing them with different ones where necessary. It also standardizes using #include <gmock/gmock.h> as opposed to #include "gmock/gmock.h" (both were being used). Each commit is one package for convenience. The code still builds and the same tests seem to be failing as before. I don't notice any improvement in build speed, so this is just a style change.

I used the clangd extension in vscode for this, though had to ignore a select few of its suggestions which caused build failures (particularly with *_impl.hpp files and similar.

---

This is an automatic backport of pull request #1199 done by Mergify.

[mergify]

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Changes to be committed:
	modified:   ackermann_steering_controller/test/test_ackermann_steering_controller.cpp
	modified:   ackermann_steering_controller/test/test_ackermann_steering_controller.hpp
	modified:   ackermann_steering_controller/test/test_ackermann_steering_controller_preceeding.cpp
	modified:   admittance_controller/include/admittance_controller/admittance_controller.hpp
	modified:   admittance_controller/include/admittance_controller/admittance_rule.hpp
	modified:   admittance_controller/include/admittance_controller/admittance_rule_impl.hpp
	modified:   admittance_controller/src/admittance_controller.cpp
	modified:   admittance_controller/test/test_admittance_controller.cpp
	modified:   admittance_controller/test/test_admittance_controller.hpp
	modified:   admittance_controller/test/test_asset_6d_robot_description.hpp
	modified:   bicycle_steering_controller/test/test_bicycle_steering_controller.cpp
	modified:   bicycle_steering_controller/test/test_bicycle_steering_controller.hpp
	modified:   bicycle_steering_controller/test/test_bicycle_steering_controller_preceeding.cpp
	modified:   diff_drive_controller/include/diff_drive_controller/diff_drive_controller.hpp
	modified:   diff_drive_controller/test/test_diff_drive_controller.cpp
	modified:   effort_controllers/include/effort_controllers/joint_group_effort_controller.hpp
	modified:   effort_controllers/src/joint_group_effort_controller.cpp
	modified:   effort_controllers/test/test_joint_group_effort_controller.cpp
	modified:   effort_controllers/test/test_joint_group_effort_controller.hpp
	modified:   force_torque_sensor_broadcaster/include/force_torque_sensor_broadcaster/force_torque_sensor_broadcaster.hpp
	modified:   force_torque_sensor_broadcaster/test/test_force_torque_sensor_broadcaster.cpp
	modified:   force_torque_sensor_broadcaster/test/test_force_torque_sensor_broadcaster.hpp
	modified:   forward_command_controller/include/forward_command_controller/forward_command_controller.hpp
	modified:   forward_command_controller/include/forward_command_controller/forward_controllers_base.hpp
	modified:   forward_command_controller/include/forward_command_controller/multi_interface_forward_command_controller.hpp
	modified:   forward_command_controller/src/forward_command_controller.cpp
	modified:   forward_command_controller/src/forward_controllers_base.cpp
	modified:   gripper_controllers/include/gripper_controllers/hardware_interface_adapter.hpp
	modified:   gripper_controllers/test/test_gripper_controllers.cpp
	modified:   gripper_controllers/test/test_gripper_controllers.hpp
	modified:   imu_sensor_broadcaster/include/imu_sensor_broadcaster/imu_sensor_broadcaster.hpp
	modified:   imu_sensor_broadcaster/test/test_imu_sensor_broadcaster.cpp
	modified:   imu_sensor_broadcaster/test/test_imu_sensor_broadcaster.hpp
	modified:   joint_state_broadcaster/include/joint_state_broadcaster/joint_state_broadcaster.hpp
	modified:   joint_state_broadcaster/test/test_joint_state_broadcaster.cpp
	modified:   joint_state_broadcaster/test/test_joint_state_broadcaster.hpp
	modified:   joint_trajectory_controller/include/joint_trajectory_controller/joint_trajectory_controller.hpp
	modified:   joint_trajectory_controller/include/joint_trajectory_controller/tolerances.hpp
	modified:   joint_trajectory_controller/src/joint_trajectory_controller.cpp
	modified:   joint_trajectory_controller/src/trajectory.cpp
	modified:   joint_trajectory_controller/test/test_load_joint_trajectory_controller.cpp
	modified:   joint_trajectory_controller/test/test_tolerances.cpp
	modified:   joint_trajectory_controller/test/test_trajectory.cpp
	modified:   joint_trajectory_controller/test/test_trajectory_actions.cpp
	modified:   joint_trajectory_controller/test/test_trajectory_controller.cpp
	modified:   pid_controller/include/pid_controller/pid_controller.hpp
	modified:   pid_controller/test/test_pid_controller.cpp
	modified:   pid_controller/test/test_pid_controller.hpp
	modified:   pid_controller/test/test_pid_controller_preceding.cpp
	modified:   position_controllers/include/position_controllers/joint_group_position_controller.hpp
	modified:   position_controllers/src/joint_group_position_controller.cpp
	modified:   position_controllers/test/test_joint_group_position_controller.cpp
	modified:   position_controllers/test/test_joint_group_position_controller.hpp
	modified:   range_sensor_broadcaster/include/range_sensor_broadcaster/range_sensor_broadcaster.hpp
	modified:   steering_controllers_library/include/steering_controllers_library/steering_controllers_library.hpp
	modified:   steering_controllers_library/include/steering_controllers_library/steering_odometry.hpp
	modified:   steering_controllers_library/src/steering_controllers_library.cpp
	modified:   steering_controllers_library/src/steering_odometry.cpp
	modified:   steering_controllers_library/test/test_steering_controllers_library.cpp
	modified:   steering_controllers_library/test/test_steering_controllers_library.hpp
	modified:   steering_controllers_library/test/test_steering_odometry.cpp
	modified:   tricycle_controller/include/tricycle_controller/tricycle_controller.hpp
	modified:   tricycle_controller/test/test_tricycle_controller.cpp
	modified:   tricycle_steering_controller/test/test_tricycle_steering_controller.cpp
	modified:   tricycle_steering_controller/test/test_tricycle_steering_controller.hpp
	modified:   tricycle_steering_controller/test/test_tricycle_steering_controller_preceeding.cpp
	modified:   velocity_controllers/include/velocity_controllers/joint_group_velocity_controller.hpp
	modified:   velocity_controllers/src/joint_group_velocity_controller.cpp
	modified:   velocity_controllers/test/test_joint_group_velocity_controller.cpp
	modified:   velocity_controllers/test/test_joint_group_velocity_controller.hpp

Unmerged paths:
  (use "git add/rm <file>..." as appropriate to mark resolution)
	both modified:   joint_state_broadcaster/src/joint_state_broadcaster.cpp
	deleted by us:   joint_trajectory_controller/test/test_assets.hpp
	both modified:   pid_controller/src/pid_controller.cpp
	both modified:   tricycle_controller/include/tricycle_controller/odometry.hpp

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