Uncertainty interval for all plot

This MR adds support to display uncertainty interval

Uncertainty interval can be displayed if the "uncertainty_column" parameter is mentioned in the data configuration. This parameter can be add with the plot configuration dialog or with the axis edit dialog :

When activated, uncertainty interval are displayed :

The uncertainty column must contain a float (or a list of float for continuous data) and interval will be defined as [y_inf, y_sup] where y_inf = y_value - uncertainty_value and y_sup = y_value + uncertainty_value