Previously, the debug manager was rewritten with the new webclient
architecture, however, because the frontend did not have access to the
new infrastructure (env and services), the old debug manager was kept
and used only in the frontend.
Since odoo/odoo#72675 the new env and services are now available, this
commit simply uses the new debug manager in the frontend and removes the
legacy code.
closesodoo/odoo#74609
Signed-off-by: Aaron Bohy (aab) <aab@odoo.com>