expose a function to extract the data for use with other plotting libraries

[g3o2]

A year ago, in eulerr version 3, I would use the combination of coef() and label() to extract the data necessary for plotting with ggplot. Now in version 5 with the label function gone, I wonder whether you could expose a function allowing to extract the data underlying the plot.

[james-chuang]

I have the same use case, and am still using eulerr 3.1.0 because of this.