EyeTracker: use information from cfg to set up and save cfg.eyetracker on shutdown

[marcobarilari]

from Remi #74

% Set calibration type.
Eyelink('command', 'calibration_type = HV5');

I think that we want to be able to define the calibration type from setParameters.

HV5: horizontal ; vertical ; 5 points H3 for horizontal calibration at 3 positions HV9 for horizontal and vertical calibration at 9 positions. We need to see what calibration type eyelink offers by default.

https://docs.google.com/document/d/1eggzTCzSHG3AEKhtnEDbcdk-2avXN6I94X8aUPEBVsw/edit?disco=AAAAB8R3onE

there are things to add in the eytracking function (see https://github.com/cpp-lln-lab/CPP_BIDS/pull/106)

• [ ] to set parameters initialized by CPP_BIDS
• [ ] to update the cfg after the setup and calibration of the eyetracker
• [ ] to save a json when shutting down so all the details of cfg.eyetracker can be saved.

TODOs flags have been added in the relevant files