Resolve "RGAA 4 - Enhance 8.10.2: display dir attribute as a evidence element"

Closes #496 (closed)

see also:

• rgaav4#155
• #479 (closed)

• Failed: no example found
• NMI:
  • https://www.spip.net/fr_rubrique91.html
  • https://www.spip.net/ar_rubrique34.html
  • https://www.spip.net/fa_rubrique58.html