Add force mode controller (backport #1049)

[mergify]

Added force mode arguments: damping and gain scaling to be usable with the force mode controller. damping and gain scaling will be changeable every time you start force mode when PR is implemented.
This is an update to PR

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This is an automatic backport of pull request #1049 done by Mergify.

[mergify]

Cherry-pick of e949995 has failed:

On branch mergify/bp/humble/pr-1049
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Changes to be committed:
	modified:   ur_controllers/CMakeLists.txt
	new file:   ur_controllers/include/ur_controllers/force_mode_controller.hpp
	modified:   ur_controllers/package.xml
	new file:   ur_controllers/src/force_mode_controller.cpp
	new file:   ur_controllers/src/force_mode_controller_parameters.yaml
	new file:   ur_controllers/test/force_mode_controller_params.yaml
	new file:   ur_controllers/test/test_load_force_mode_controller.cpp
	new file:   ur_robot_driver/examples/examples.py
	new file:   ur_robot_driver/examples/force_mode.py
	new file:   ur_robot_driver/test/integration_test_force_mode.py
	modified:   ur_robot_driver/test/test_common.py

Unmerged paths:
  (use "git add/rm <file>..." as appropriate to mark resolution)
	both modified:   ur_controllers/controller_plugins.xml
	both modified:   ur_controllers/doc/index.rst
	both modified:   ur_robot_driver/CMakeLists.txt
	both modified:   ur_robot_driver/config/ur_controllers.yaml
	deleted by us:   ur_robot_driver/doc/usage/controllers.rst
	both modified:   ur_robot_driver/include/ur_robot_driver/hardware_interface.hpp
	both modified:   ur_robot_driver/launch/ur_control.launch.py
	both modified:   ur_robot_driver/src/hardware_interface.cpp
	deleted by us:   ur_robot_driver/test/integration_test_controller_switch.py
	both modified:   ur_robot_driver/test/robot_driver.py
	deleted by us:   ur_robot_driver/urdf/ur.ros2_control.xacro

To fix up this pull request, you can check it out locally. See documentation: https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/reviewing-changes-in-pull-requests/checking-out-pull-requests-locally