make flexible which direction to show in `setParameters`

[marcobarilari]

at the moment, directions to show are a 'constant' in expDesign>getDirectionBaseVectors

function [MOTION_DIRECTIONS, STATIC_DIRECTIONS] = getDirectionBaseVectors(cfg)

    % CONSTANTS
    % Set directions for static and motion condition

    STATIC_DIRECTIONS = [-1 -1 -1 -1];

    switch cfg.design.motionType
        case 'translation'
            MOTION_DIRECTIONS = [0 90 180 270];
        case 'radial'
            STATIC_DIRECTIONS = [666 -666 666 -666];
            MOTION_DIRECTIONS = [666 -666 666 -666];
    end

end