Add functional preprocessing script utilizing ICA+FIX

[SiemondeLange]

Add a default preprocessing script that uses FSL to apply ICA+FIX for rs-fMRI preprocessing.

[SiemondeLange]

The current example preprocessing script for ICA+FIX provides the expected output files. However, the correct implementation of the ICA+FIX has not been validated as this requires a dataset-specific trainings file (e.g. Standard.RData).

I have no reference dataset with such trainings-file at the moment and will postpone the implementation of an example ICA+FIX preprocessing file to a later CATO version. This will ensure proper testing of this feature and adequate documentation for users about this dataset-specific processing step.

[SiemondeLange]

It might be a good idea to include this preprocessing step as an "add-on". That might be appropriate considering that it is an extension of CATO, uses additional external software and additional parameters.