Add Error column to the list of completed jobs on the landing page

Purpose:
In order to provide a better feedback to the user about the state of the exported records we will need to display the number of the records that failed to be processed. For example if the user wanted to export 500 records and 5 records failed, the Error column will let the user know about that number. The job will still have a status failed. Making the exported file for a failed job accessible is covered by UIDEXP-98

Scenario 1:
Given: the export job execution completes
When: not all records were exported successfully
Then: The Records column contain the number of the records that were requested for the export. The Errors column contains the number of the records that failed the export.

Scenario 2:
Given: the export job execution completes
When: all records were exported successfully
Then: The Records column contain the number of the records that were requested for the export. The Errors column is empty

Scenario 3:
Given: the export job execution completes
When: none of records were exported successfully
Then: The Records and Errors column are empty