Boxplot in Normality & Homoscedasticity view

Boxplot has been added to the Normality & Homoscedasticity view as a quick way to compare the values of the different groups.
Barplot in Normality & Homoscedasticity view

Barplot with error bars has been added to the Normality & Homoscedasticity view as a quick way to compare the values of the different groups.
Code clean