Implement sort by start/end/cancellation dates in Agreements search and sort MCL

Purpose:

User story statement(s):

As a erm user,
I want to be able to sort a list of agreements by start date
so that I can see the agreements with the most or least recent start date easily in a list of results

Scenarios:

1. Scenario:
   • Given a set of search results in the Agreements search and sort MCL
   • AND the results not already sorted by start date
   • When the "Start date" column heading is clicked
   • Then the results will be sorted by date ascending
2. Scenario:
   • Given a set of search results in the Agreements search and sort MCL
   • AND the results already sorted by start date
   • When the "Start date" column heading is clicked
   • Then the reverse sort order will be applied on the Start date column
3. Scenario:
   • Given a set of search results in the Agreements search and sort MCL
   • AND the results not already sorted by end date
   • When the "End date" column heading is clicked
   • Then the results will be sorted by date ascending
4. Scenario:
   • Given a set of search results in the Agreements search and sort MCL
   • AND the results already sorted by end date
   • When the "End date" column heading is clicked
   • Then the reverse sort order will be applied on the End date column
5. Scenario:
   • Given a set of search results in the Agreements search and sort MCL
   • AND the results not already sorted by cancellation deadline
   • When the "Cancellation deadline" column heading is clicked
   • Then the results will be sorted by date ascending
6. Scenario:
   • Given a set of search results in the Agreements search and sort MCL
   • AND the results already sorted by cancellation deadline
   • When the "Cancellation deadline" column heading is clicked
   • Then the reverse sort order will be applied on the Cancellation deadline column

Other information

The option to sort this MCL by date field was previously removed because it was not possible to sort by the displayed dates. Following the changes to the date management on Agreements, it is now possible to sort by these dates.

In the UI the parameters:

• sort=startDate
• sort=-startDate
• sort=endDate
• sort=-endDate
• sort=cancellationDeadline
• sort=-cancellationDeadline

already work, but there are no UI controls for applying these sorts (these translate to sort=startDate%3Basc and sort=startDate%3Bdesc etc. respectively in the backend request)