🔨 improvements:

Change get__type__ to return a set of values. It is defined at the Converter level despite only returning a value for a small number of Converters but it simplifies the code using it to do so that way.

Validation and validator can be set on converters after initialization. Only some converter makes use of those values. This makes the message_to_odoo_validate method unnecessary, that’s why it has been removed.

--HG-- branch : 13.0