Clicking the media button failed to open the media modal. The reason was
that initializing the media modal involved triggering an RPC to fetch
attachments but that resulted in a never-resolving promise because
`trigger_up('call_service')` was never caught. That is because
`website_forum` failed to pass itself as parent of `wysiwyg` when
instantiating the editor, thus breaking the chain that should have led
to `public_root`, which listens to `'call_service'` custom events.
closesodoo/odoo#62991
Signed-off-by: David Monjoie (dmo) <dmo@odoo.com>