Extend use case 2.1 to multiple value output

[robertoostenveld]

This is following discussion with @schoffelen regarding resampling to achieve differential privacy in the results.

Right now it only computes the mean age. The data also contains many other variables, like sex, Height, Weight (*), and a number of questionaire outcomes. I suggest to include height and weight, which gives three variables between which I would anticipate some (but not too much) correlation.

The output results.txt should be reformatted to not include any headers.

(*) Note that Height and Weight are both present in the participant.tsv starting with a capita, whereas age and sex are without capitall

[robertoostenveld]

Use case 2.1 is probably at the moment also the easiest to convert into a container using apptainer.

[robertoostenveld]

and it should be modified to take the input BIDS directory as argument, not the input participants.tsv