In the UE, we wish to handle ^C in the UE to send a message before
terminating, so we allow custom wait handlers to implement such
functionality. Use itti_wait_tasks_unblock() to unblock
itti_wait_tasks_end().

Also, implement itti_wait_tasks_end() using semaphores, as signals are
not async-signal-safe (and therefore should not be used in a signal
handler).

integration_2023_w10b

See merge request oai/openairinterface5g!2002

* !1954 Fix for warnings and errors from CLANG compiling
* !1978 Change default of "nokrnmod" option to "On"
* !1981 F1AP: minor fixes and preparation for F1 work
* !1983 Improve clang-format
* !1992 fix nrqtscope build warnings
* !1994 reworking response to MSG3 with DCCH/DTCH
* !1996 dead-code-f1-removal
* !1968 small changes for multi usrp support
* !1991 rfsimulator: configurable wait timeout, use in CI to avoid retransmissions
* !1999 Remove Dedicated Serving Cell Configuration from CI config file for 2x2 rfsim test

traceFd of thread pool can be:
* -1: no tracing
* valid file descriptor/>0: tracing