The dependencies of the public_root module were recently updated, but
the manifest of im_livechat was not, causing it to fail to load. This
commit adds those missing dependencies to the manifest.
This commit also adds a test that checks that all modules are properly
loaded on the support page, since this has been broken on multiple
occasions while changing the dependencies or the path of some of the
modules this page needs to work.
closesodoo/odoo#74756
Signed-off-by: Sébastien Theys (seb) <seb@odoo.com>