* Add Style.HideHeaders to TableView
* Revisions to TableView HideHeaders from review
Also add to UICatalog TableEditor Scenario
* Allow ShowHorizontalHeaderUnderline to draw top border even when HideHeaders is enabled; AlwaysShowHeader will keep it there on scroll
* Add Unit Tests for TableView.Style.HideHeaders
* Rename HideHeaders to ShowHeaders and simplify logic
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Co-authored-by: tznind <tznind@dundee.ac.uk>