Generic functionality to print stuff when mousing hover map?

[remicousin]

Currently we have a functionality to print the lowest admin level. It's been requested to maybe print the map value(s -- if more than one layer?). We typically would not want to pop this information over the map because that's typically not great for map readability. So instead we might try and think of some generic Maproom layout where to put this type of information. We should differentiate it with the information obtained when clicking on the map. We didn't have mouse-hover functionality in classic Maprooms so it's new.