[MOV] tools: put _neuter_mimetype from Document app
[MOV] tools: put _neuter_mimetype from Document app

This method will be used later in other module(s) than Document.

Task : 1960733
ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo