Better legends and labels for Query Builder Widget

This is really a few pieces of improvement:

1. When the query builder widget is used on a dashboard, it strangely does not show any legend. You have to mouse-over the graph to see what the graph components mean. You should add an option to show the legend by default.
    
2. We should be able to customize the legends and labels. Right now for bar charts, they have a non-human readable format like “E1A1”. We should be able to customize the labels, otherwise these widgets will have extremely limited usability:

   

3. Similar suggestion for the mouse-over tooltip/labels on the other chart types. We should be able to customize the labels rather than being stuck with the default “E1 [name] - A1 [name] | [Value]” format. It’s not useful for most people, and makes me not want to use the query builder widgets because the dashboards will look unpolished and unprofessional.