The odoo.addons.web.controllers.main python module have been splitted
over multiple files on the basis 1 controller = 1 file. In this work we
adapt all modules to use the new imports.
A non-exhaustive list of where stuff have been moved:
* main.Home --> home.Home
* main.Session --> session.Session
* main.WebClient --> webclient.WebClient
* main.clean_action --> action.clean_action
* main.ensure_db --> home.ensure_db
The complete list is accessible in odoo.addons.web.controllers.main.
closesodoo/odoo#87571
Related: odoo/enterprise#25746
Signed-off-by: Raphael Collet <rco@odoo.com>