[ticket/12476] Increase asset version on cache purge

Increace the asset version when purging the cache from "ACP > General"

PHPBB3-12476
[ticket/12476] Increase assets also from acp_styles and phpbbcli

Increase assets also from "ACP > Styles > Purge Cache" and phpbbcli

PHPBB3-12476
[ticket/12476] Label the constructor as public

Label the the constructor as public.

PHPBB3-12476