[REM] web: remove unused controller /apps/<app>

This controller never really worked in the last 3 versions.
It was fixed in 11.3 with e9350993 but broken with refactoring in 12.0 at a
higher level with 19eacf7d.

It was even worse in 13.0 as it was leading to a traceback: `view_type` field
got removed with 3cd7ed07 but this controller was still reading that
field.

closes odoo/odoo#38173

Signed-off-by: Jérémy Kersten (jke) <jke@openerp.com>