Description of problem:
- The export (XLS/CSV format) functionality in the Dashbuilder currently exports all of the columns defined in the data source table for a report table in the UI as opposed to exporting only the columns that are currently visible or which has been configured in that table in the UI. Ideally, Dashbuilder should only export (XLS/CSV) data columns which is visible or configured by user, not for the entire data source.

Version-Release number of selected component (if applicable):
- BPMS 6.0.2

How reproducible:
- Always

Steps to Reproduce:
1. Log in to Dashboard Builder which should land you to the "Home" Page
~~~
http://localhost:8080/dashbuilder/
~~~
2. Click on "Sample dashboards" from your left hand panel.
3. Click on "Sales opportunities" and under that you would find "Sales report" as a tabular report. Click on "Sales report" now.
4. You should find a table containing lot of columns and they are fetched from "Sales dashboard demo" data provider which pulls those many columns from a data source and pushes it to the table which we are seeing right now.
5. On the upper and extreme right side of that panel where the table is shown , contains a small but greyed out button as shown in the private snapshot. Clicking it should bring down a drop-down. Click on "Edit content" option and it should show you the "Panel Edition" window as shown in screenshot "PanelEdition.png".
6. Now on the right hand side it shows you the columns which are displayed. After each column name there is a tiny symbol (probably the second option) which reads "Delete this column" , as shown here in "DeleteColumnPanelEdition.png" . Clicking on it will enable you to reduce the number of columns being displayed on your display table. Now try to delete as many columns as you want. Close the window and now after the panel is refreshed you should see the number of columns have been reduced , just as you wanted.
7. Now, try to do Export to xls or CSV , and you would find that the exported report still contains the entire table with those columns in it as well which you removed above . Refer to the screenshot "XLScontainingolddata.png" for reference.


Actual results:
- Dashbuilder exports all of the columns defined in the data source table.

Expected results:
- Only the selected or configured table columns should be exported.

Additional info:
- NA