Handle Talkback a11y in a list with sticky headers

I've tested the accessibility context with this new implementation and in the Border token page, when browsing down the list, there is an issue when going back up.

https://github.com/user-attachments/assets/38ed5448-54f7-4cbf-b5cf-613d2ec46add

when on the last item before the title, it goes to the title, then one more up it goes to the theme selector and not the next item up. Is it possible to go up the page instead?
what do you think @afrahB?

For accessibility, I also found:

• the text reading should read each list item token as one reading instead of reading each text separately
• the next item in the screen to read after the header is not the back, but the content within the page

Originally posted by @B3nz01d in #206

First point has been fixed, need to fix the second on if the accessibility team agrees.

Start by reproducing the TalkBack behavior described for the list with sticky headers, especially the Border token page and navigation after the header. Inspect the accessibility behavior of the list and header; done means TalkBack moves from the header into the page content in the intended order and reads each token item as one unit.