Improve Superset logger (#6879)

* enable beacon

* add middleware

* add unit tests

superset/assets/spec/javascripts/dashboard/components/gridComponents/Chart_spec.jsx

@@ -54,6 +54,7 @@ describe('Chart', () => {
     refreshChart() {},
     toggleExpandSlice() {},
     addFilter() {},
+    logEvent() {},
     editMode: false,
     isExpanded: false,
     supersetCanExplore: false,

superset/assets/spec/javascripts/dashboard/components/gridComponents/Markdown_spec.jsx

@@ -51,6 +51,7 @@ describe('Markdown', () => {
     handleComponentDrop() {},
     updateComponents() {},
     deleteComponent() {},
+    logEvent() {},
   };
 
   function setup(overrideProps) {

superset/assets/spec/javascripts/dashboard/components/gridComponents/Tabs_spec.jsx

@@ -52,6 +52,7 @@ describe('Tabs', () => {
     onChangeTab() {},
     deleteComponent() {},
     updateComponents() {},
+    logEvent() {},
   };
 
   function setup(overrideProps) {