[FIX] base/ir_model: fix materialized views columns listing

When there is a materialized view that has not been populated any select
on it will fail.

Example of traceback:
```
Traceback (most recent call last):
  File "/home/odoo/src/odoo/12.0/odoo/service/server.py", line 1162, in preload_registries
    registry = Registry.new(dbname, update_module=update_module)
  File "/home/odoo/src/odoo/12.0/odoo/modules/registry.py", line 86, in new
    odoo.modules.load_modules(registry._db, force_demo, status, update_module)
  File "/home/odoo/src/odoo/12.0/odoo/modules/loading.py", line 367, in load_modules
    registry.setup_models(cr)
  File "/home/odoo/src/odoo/12.0/odoo/modules/registry.py", line 262, in setup_models
    env['ir.model']._add_manual_models()
  File "/home/odoo/src/odoo/12.0/odoo/addons/base/models/ir_model.py", line 321, in _add_manual_models
    cr.execute('SELECT * FROM %s LIMIT 0' % Model._table)
  File "/home/odoo/src/odoo/12.0/odoo/sql_db.py", line 148, in wrapper
    return f(self, *args, **kwargs)
  File "/home/odoo/src/odoo/12.0/odoo/sql_db.py", line 225, in execute
    res = self._obj.execute(query, params)
psycopg2.errors.ObjectNotInPrerequisiteState: materialized view "x_bi_sql_view_report_copy" has not been populated
HINT:  Use the REFRESH MATERIALIZED VIEW command.
```

Several upgrade requests have or had had this error which has been
solved with specific scripts.

Related to #40930

closes odoo/odoo#69367

Signed-off-by: Raphael Collet (rco) <rco@openerp.com>