[Bug][Tabstrip] Tabstrip does not update the :focus state when a new tab is selected

[vveesseelliinnaa]

I'm submitting a...

• Bug report

Current behavior

When the user navigates through the tab via the keyboard arrows or mouse click, the focus state of the tabs is not updated and the focus-related styles are not applied, respectively.

Expected behavior

The focus state should be updated and the style of the selected tab should be the same like if the tab is clicked (refer the Angular Tabstrip).

Minimal reproduction of the problem with instructions

1. Go to https://www.telerik.com/kendo-vue-ui/components/layout/tabstrip/keyboard-navigation/
2. Click on the Paris tab
3. Press the right arrow button

Result: The selected tab is changed but the focus state is not updated

Additional details

Reported in Ticket ID: 1632439