TabStrip does not have visual indication for focus

[kendo-bot]

When focusing the component a visual indication aims to show the user that something has changing during keyboard navigation. In the TabStrip there is no such indication. This also violates WCAG 2.4.7.

Moreover, there is no indication when a tab content is focused. The focus on the Tab content is available starting from R1 2021:
#5871

https://demos.telerik.com/kendo-ui/tabstrip/keyboard-navigation

Waiting for: https://github.com/telerik/kendo-ux/issues/18

Environment

Kendo UI: 2020.2.617
Browser: all