Use NS weights for posterior plots and quantiles
If working with the outputs of nested sampling code and we have the weights stored in the Result
object we should allow the plot_corner
function to use all the nested samples, but with weights applied (as is done in dynesty and ultranest). This will reduce the sampling noise especially in the wings of the posteriors. We should also look at the dynesty quantile function, which will use the weights to work out quantiles, which again should reduce the random noise on the values.