[FIX] fields: when executing (4, *) operations on o2m fields, check the existence based on the sql model of the table.

If the o2m field linked to the o2m is stored on a different table (eg: inherit), previous request would crash as the field do not exists in the '_table' sql table
[FIX] parent_model is null if local column
[FIX] fields: when executing (4, *) operations on o2m fields, check the existence based on the sql model of the table.

If the o2m field linked to the o2m is stored on a different table (eg: model with _inherit), previous request would crash as the field do not exists in the '_table' sql table