[IMP] account: add prepare methods for exchange diff move lines
[IMP] account: add prepare methods for exchange diff move lines

Such prepare methods are useful in situations where we want to propagate some
analytic dimension to exchange difference move.

Closes #16282

ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo