Add size or allow hue to support quantitative values in UMAP_Panel function

[spficklin]

When running this code:

gsf.panels.UMAP_Panel(gsc, hue="Treatment", random_state=42, n_neighbors=474,
                                  interface_opts={"count_variable": "uq_counts", 
                                                  "selected_gene_sets": ["Treatment"]}).view()

Is there way to either

1. Allow hue to support quantitative columns (e.g. Duration Time) to color with a gradient
2. Add a size argument to size the points by a quantitative columns