plotHeatmap: support ordered factors in sampleData in the legend?

[allonw]

1. Can plotHeatmap take account of the order of ordered factors when plotting them in the legend?
2. When one of the sampleData metadata has spaces, plotHeatmap breaks with an error that doesn't report what's wrong

library(clusterExperiment)

aaa = matrix(runif(100), nrow = 10)
anno = factor(sample.int(3, size = 10, replace = TRUE), ordered = TRUE)
levels(anno) = c("low activity", "medium activity", "high activity")

#Error in cut.default(a, breaks = 100) : 'x' must be numeric
plotHeatmap(data = aaa, sampleData = as.data.frame(anno))

#works, but ignores the order of the factor
plotHeatmap(data = aaa, sampleData = as.data.frame(make.names(anno)))

[epurdom]

I missed the error part of this. So I opened the error as a separate issue and adjusted the title.

[epurdom]

Because problem with ordered factors in aheatmap (#184) have not added this yet as enhancement.