Add a way to suspend and resume user tasks.

...dules/owntech_scheduling/zephyr/public_api/Scheduling.cpp

...modules/owntech_scheduling/zephyr/public_api/Scheduling.h

...ules/owntech_scheduling/zephyr/src/asynchronous_tasks.cpp

...ules/owntech_scheduling/zephyr/src/asynchronous_tasks.hpp

...dules/owntech_scheduling/zephyr/src/scheduling_common.cpp

...dules/owntech_scheduling/zephyr/src/scheduling_common.hpp

...cheduling/zephyr/src/uninterruptible_synchronous_task.cpp

...cheduling/zephyr/src/uninterruptible_synchronous_task.hpp

...yr/modules/owntech_timer_driver/zephyr/public_api/timer.h

...ules/owntech_timer_driver/zephyr/src/stm32_timer_driver.c

...ules/owntech_timer_driver/zephyr/src/stm32_timer_driver.h