addition of a comparison_type modality in the function vector_comparison.R

[esthermollier]

Add a modality of comparison_type where we compare column A to B and we check if A is “>”, “>=”, “<”, “<=”, “≠”, “==” to B. “==” would be the equivalent of the modality 'equality' of comparison_type

[OceaneBouhineauIRD]

Possible value for comparison_type: "difference", "equal", "less", "greater", "less_equal" or "greater_equal"
Done