This commit fixes all issues detected by the new pylint
gettext-variable test.
It converts some calls to the new syntax
  _("Foo %s", bar)

to progressively migrate the code to the new syntax.

A few calls were not technically incorrect but still detected by the
linter.

  _("Foo" +
    "Bar")

has been converted to

  _("Foo"
    "Bar")

as it has the same effect and make sure the argument is of type
asteroid.Const instead of BinOp).

closes odoo/odoo#53683

Related: odoo/enterprise#11467
Signed-off-by: Raphael Collet (rco) <rco@openerp.com>