Fixed problem in ResultsetTable when sortValue is missing

[Mil4n0r]

Checklist
(Check off all the items before submitting)

• Build process is done without errors. All tests pass in the /lib directory.
• Self-reviewed the code before submitting.
• Meets accessibility standards.
• Added/updated documentation to /website as needed.
• Added/updated tests as needed.

Description
SortValue must take displayValue instead if it is undefined. After changing the structure adding the "cells" item, this is not working.

[Mil4n0r]

I will be adding interaction tests for this scenario to prevent it from happening again.

[jsuarezgonz]

Please add a functional test to check that the columns are correctly sorted according to 'displayValue' when 'sortValue' is undefined