NICOS: Allow a mechanism to kill arbitrary code

As an instrument scientist I would like to be able to stop any running code in an emergency. We can do this with genie_python code using (https://github.com/ISISComputingGroup/IBEX/issues/3036) but NICOS cannot do it with code such as the standard sleep(). This is because this code is blocking in the underlying C (which python cannot interrupt). We should investigate how much this affects code being run in:
* Numpy
* Mantid
* CaChannel

There are some potential options for this:
* Make sure scientists are aware and warn them that code not in genie_python is unsafe in this way (this is what FRM-II do)
* Allow scientists to kill the daemon entirely from the GUI (procserv?)
* Modify NICOS in some way to allow for killing the script (either find a way to kill the thread or start it in a new process)