fix(#3668): Added default eventHandler to viewPortKeyDown (#6413)
fix(#3668): Added default eventHandler to viewPortKeyDown (#6413)

When overriding the default cell navigation, you will in some cases still need to trigger the default event handler. This small change lets the developer retrigger the default behaviour if needed.
angular-ui/ng-grid,angular-ui/ui-grid,AgDude/ng-grid,angular-ui/ng-grid,Servoy/ng-grid,Servoy/ng-grid,angular-ui/ng-grid,angular-ui/ui-grid,AgDude/ng-grid,AgDude/ng-grid,angular-ui/ui-grid,Servoy/ng-grid