Rewrite code parsing name (_parse_partner_name) to make it easier to
understand. Tweak find_or_create to return directly a recordset with the
found partner / new partner instead of a name_get result.
Also inherit Partner.find_or_create() in mail in order to benefits from
email_normalized field, allowing to improve the search on matching emails
and avoid duplicates.
LINKS
Task ID 1963529
Community PR odoo/odoo#32397
