Fix Export CSV Action in Retention Search page

.loSteps to reproduce:

• User navigates to Retention > Retention search
• User has some documents appearing in the lower panel
• User clicks "Export CSV"

Expected behaviour:

• There is a notification that reads "CSV Export is running", followed by another saying "CSV Export is ready"
• CSV file is downloaded

Actual behaviour:

• There is only a notification that reads "CSV Export is running".
• The second notification never appears
• The document isn't downloaded