Segmented button keyboard navigation

[InnaAtanasova]

Currently the Segmented button has the "checkbox" behaviour where the next element is focussed using the Tab key. In UI5 the "radio button" behaviour is used where the Tab focusses the first element and then the navigation is done using the arrow keys.

For more information: https://ej2.syncfusion.com/documentation/button-group/accessibility/

We need to discuss both implementations and how to provide an option to the user to pick one (if we decide to implement both)