feat: better download for conversation traffic heatmap (#6755)

* feat: genearte report in a grid

* refactor: update API usage

* refactor: separate generate method

* refactor: abstract transform_data

* feat: annotate with comments

* feat: add explicit timezone

* feat: download data only in user timezone

* fix: dates included in heatmap

app/javascript/dashboard/store/modules/reports.js

@@ -180,7 +180,7 @@ export const actions = {
       });
   },
   downloadAccountConversationHeatmap(_, reportObj) {
-    Report.getConversationTrafficCSV(reportObj)
+    Report.getConversationTrafficCSV()
       .then(response => {
         downloadCsvFile(
           generateFileName({