Add additional checks for non existing and not available interfaces. (backport #1218)

[mergify]

This is an automatic backport of pull request #1218 done by Mergify.
Cherry-pick of 8c34ab6 has failed:

On branch mergify/bp/humble/pr-1218
Your branch is up to date with 'origin/humble'.

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  (fix conflicts and run "git cherry-pick --continue")
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Changes to be committed:
	modified:   hardware_interface/CMakeLists.txt
	modified:   hardware_interface/include/hardware_interface/resource_manager.hpp
	modified:   hardware_interface/test/test_components/test_actuator.cpp
	modified:   hardware_interface/test/test_hardware_components/test_system_with_command_modes.cpp
	new file:   hardware_interface/test/test_resource_manager.hpp
	new file:   hardware_interface/test/test_resource_manager_prepare_perform_switch.cpp

Unmerged paths:
  (use "git add <file>..." to mark resolution)
	both modified:   hardware_interface/src/resource_manager.cpp
	both modified:   hardware_interface/test/mock_components/test_generic_system.cpp
	both modified:   hardware_interface/test/test_resource_manager.cpp

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

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