Add an option to run tasks so they raise an error during the run

[oliche]

Currently tasks catch errors and output the traceback.
For some manual processing and or scripts, it is useful to halt execution and raise during the task.

The on_error parameter at the init stage is set to continue by default, and can be set to raise to achieve this behaviour.

[oliche]

Look at run_alyx tasks that may benefit from using this

[k1o0]

Look at run_alyx tasks that may benefit from using this

ibllib/ibllib/pipes/tasks.py

Lines 912 to 914 in e110a24

	task.cleanUp()
	if mode == 'raise' and status != 0:
	raise ValueError(task.log)

Interestingly this cleans up the task before re-raising