Confirm merit list and task helper functions logic and tests

[KoWeiJAC]

Background

When adding tests of #2529, found there are some logic having conflicts, it may because of the merit list is developing.
If the merit list is finished, it may worth to confirm following logic conflicts still remain or not.

In src/views/Exercise/Tasks/Task/Finalised/meritListHelper.js

• totalPassed(task, scoreType, scores)
  • Confirm if this change work. This change is for the function can accept the return values of scores(task, scoreType, exerciseDiversity) for scores parameter and pass the tests.
  • related tests
    • [totalPass] should calculate total passed correctly without overrides
    • [totalPass] should calculate total passed correctly with overrides
    • [scores] should correctly calculates cumulative diversity data
  
• xlsxData(didNotTake, failed, task, diversityData, type)
  • Confirm this nested condition blocks using the same type parameter comparing with different constants, the inner block may never be excuted.
  • Related test:
    • [downloadMeritList] should handle QUALIFYING_TEST type correctly
  
• getDownloadTypes(task)
  • Confirm if task affect the download types.
  

In src/helpers/taskHelper.js

• function markingScheme2ColumnHeaders(markingScheme)
  • Confirm if other marking schema type needs to add headers as well to match the function markingScheme2Columns(markingScheme, editable = false) logic
  • Related tests:
    • [markingScheme2ColumnHeaders] should generate correct headers for a simple marking scheme
    • [markingScheme2ColumnHeaders] should handle mixed types correctly
    • [markingScheme2ColumnHeaders] should handle multiple groups and non-group items