feat: Introduce IsDataPanel attribute to plugin.json

pkg/api/frontendsettings.go

@@ -145,6 +145,7 @@ func (hs *HTTPServer) getFrontendSettingsMap(c *m.ReqContext) (map[string]interf
 			"info":         panel.Info,
 			"hideFromList": panel.HideFromList,
 			"sort":         getPanelSort(panel.Id),
+			"isDataPanel":  panel.IsDataPanel,
 		}
 	}