Remove spinlock from threadpool task return
The idea to use atomic aligned to cache line for counting finished jobs
is reused, but instead of polling a semaphore was added.
- removed some whitespace noise.
- cleaned up CMakeLists.txt
- reintegrated task_manager.c into thread-pool.c
- cleaned up some unnecessary code
Co-authored-by: Cedric Roux <cedric.roux@eurecom.fr>
Co-authored-by: Mikel Irazabal <mikel.irazabal@openairinterface.com>