Remove progressbar.js dependency from com_finder (admin)

#### Use the bootstrap javascript for rendering the progress bar

`bootstrap.framework` is always loaded in ISIS and HATHOR so it’s better to use that library instead of loading one more script!

#### B/C
The html markup is changed
The relative css file is not loaded anymore
The relative js file is not loaded anymore

#### Testing
To test this make sure you have plenty of data!
Apply the patch with patch tester ( make sure you are on staging)
purge the indexes if there are any
Re index, and observe that the progress bar is still there, working


You can remove the entire method if all it's doing is calling the parent method - just have an empty class!