XWIKI-9093: Extensions are badly displayed in the last step of Distribution Wizard
(cherry picked from commit 02be5f25e092b933be9fb57015e5df7598131038)
XWIKI-9094: The Continue step button is displayed in the last step of Distribution Wizard even if there are invalid extensions to fix
(cherry picked from commit 0e53058f298de4742b8a10440f0941ac50f0db1e)