Before the forum redesign, the .container element which contains the
forum navbar had the 'website_forum' class. Now this class was moved
to encapsulate the whole forum page.
Problem is that themes were styling that container element specifically
and the `#wrap` element of the forum by respectively targeting
`.website_forum` and `.website_forum + #wrap`. This commit solves this
by adding a 'o_wforum_navbar_container' class on the element allowing
to modify the themes selector with `.o_wforum_navbar_container` and
`.website_forum #wrap`.
closesodoo/odoo#29581
qsm-odoo
0794a3c956