[IMP] *: don't format integers in the relevant cases

It is now possible not to format integers according to locale
This is particularly interesting and relevant when a number holds
some sort of code rather than a number

Task 2050119

*: base, fetchmail, l10n_cl

closes odoo/odoo#39767

Related: odoo/enterprise#6964
Signed-off-by: Aaron Bohy (aab) <aab@odoo.com>