Fix tooltips for SVGs generated by visualize() in Jupyter notebooks (#663)

Author: tomwhite

cubed/core/plan.py

@@ -473,7 +473,7 @@ def visualize(
             import IPython.display as display
 
             if format == "svg":
-                return display.SVG(filename=full_filename)
+                return display.HTML(filename=full_filename)
         except ImportError:
             # Can't return a display object if no IPython.
             pass