Application List Sorting

### User Stories
As an Examiner
I want to be able to change the sort order based on the values of the columns
So that I can see items based on my specific workflow tasks

### Acceptance Criteria
- [ ] Scenario: Sorting by Payment Completed Date
- Given I an logged in as an Examiner
- When I click the 'Submitted Date' Header
- Then the sort order of dates is reversed

Start by locating the application list and its column-header sorting entry point. Compare the requested Submitted Date behavior with the acceptance criterion mentioning Payment Completed Date, then verify the intended date-column sort interaction. Done means clicking the relevant header reverses the date order consistently.

Written by the indexing model from the issue text.