Normalize the quantity before calculating the number of digits when parsing UBL

Trailing zero in the quantity should not require a bigger precision for the
unit.

Closes #14973
(grafted from 763adbca3986db5acffd5631821fe9647bb5b2f4)

--HG--
branch : 8.0

modules/edocument_ubl/edocument.py

@@ -460,7 +460,9 @@ class Invoice(Model):
         if (invoiced_quantity := invoice_line.find('./{*}InvoicedQuantity')
                 ) is not None:
             line.quantity = float(invoiced_quantity.text)
-            digits = -Decimal(invoiced_quantity.text).as_tuple().exponent
+            digits = (
+                -Decimal(invoiced_quantity.text)
+                .normalize().as_tuple().exponent)
             if (unit_code := invoiced_quantity.get('unitCode')) not in {
                     None, 'ZZ', 'XZZ'}:
                 try:
@@ -771,7 +773,9 @@ class Invoice(Model):
         if (credited_quantity := credit_note_line.find('./{*}CreditedQuantity')
                 ) is not None:
             line.quantity = -float(credited_quantity.text)
-            digits = -Decimal(credited_quantity.text).as_tuple().exponent
+            digits = (
+                -Decimal(credited_quantity.text)
+                .normalize().as_tuple().exponent)
             if (unit_code := credited_quantity.get('unitCode')) not in {
                     None, 'ZZ', 'XZZ'}:
                 try: