swap 'id' for 'pointNumber' in scattergl selection data

- to match svg 'scatter'

Author: etpinard

src/traces/scattergl/convert.js

@@ -562,7 +562,7 @@ proto.updateFancy = function(options) {
     if(selection) {
         selIds = {};
         for(i = 0; i < selection.length; i++) {
-            selIds[selection[i].id] = true;
+            selIds[selection[i].pointNumber] = true;
         }
     }
 

src/traces/scattergl/select.js

@@ -40,7 +40,7 @@ module.exports = function selectPoints(searchInfo, polygon) {
             y = ya.c2p(di.y);
             if(polygon.contains([x, y])) {
                 selection.push({
-                    id: i,
+                    pointNumber: i,
                     x: di.x,
                     y: di.y
                 });