The move to defer amount must be created before creating the period move in
case we need to compute the remainder amount on the first run.
Closes#13547
(grafted from e4758cb22bff649346d546ff0645c165b4b3c2b8)
--HG--
branch : 7.0
The post method can be called multiple times for an invoice by process but
only one deferral is allowed by line.
Also the initial draft deferral may be delete in case of mistake so we must
not create automatically a new one later.
Closes#12567
Cédric Krier