Bind graph using the DOM element instead of id

Billboard must receive the graph element directly because the chart can be
rendered while it is still detached from the document.

Closes #14970
(grafted from 00123388953eb5d0e7cee0ff3b8d005a826db9e9)

--HG--
branch : 8.0

sao/src/view/graph.js

@@ -69,7 +69,6 @@
             this.xfield = xfield;
             this.yfields = yfields;
             this.el = jQuery('<div/>');
-            this.el.uniqueId();
         },
         update_data: function(group) {
             var data = {};
@@ -171,7 +170,7 @@
         _bb_config: function(data) {
             var bb_config = {};
 
-            bb_config.bindto = '#' + this.el.attr('id');
+            bb_config.bindto = this.el.get(0);
             bb_config.data = data;
             bb_config.data.type = this._chart_type;
             bb_config.data.x = 'labels';