New threadpool

- 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>

common/utils/threadPool/CMakeLists.txt

@@ -1,6 +1,6 @@
 if (ENABLE_TESTS)
   add_subdirectory(test)
 endif()
-add_library(thread-pool thread-pool.c)
+add_library(thread-pool thread-pool.c task_ans.c)
 target_link_libraries(thread-pool PRIVATE utils)
 target_include_directories(thread-pool PUBLIC .)