RFR: 8359257: Create accessibility protocol for TabGroup component [v2]

[Andy Goryachev]

On Thu, 12 Jun 2025 18:36:31 GMT, Alexander Zuev <kizune at openjdk.org> wrote:

>> Create implementation of the TabGroup protocol and assign it to TAB_PANE and PAGINATION roles.
>
> Alexander Zuev has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Fixing indentation.

Also noticed to pre-existing issues (in master):
- resizing the control does not update the accessibility focus rectangle
- flipping through tabs in TabPane using left/right arrow keys sometimes places the accessibility focus rectangle in a wrong location.

Since I cannot take a screenshot with the accessibility focus rectangle, here is the artistic depiction:

![Screenshot 2025-06-12 at 12 05 05](https://github.com/user-attachments/assets/e3e70916-b9cd-472a-b387-aeb5ca3e65c2)

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PR Comment: https://git.openjdk.org/jfx/pull/1823#issuecomment-2967907959