Make consumption quantity required

It is needed to compute the quantity to invoice.

issue10138
review341981002

subscription.py

@@ -869,7 +869,7 @@ class LineConsumption(ModelSQL, ModelView):
         'sale.subscription.line', "Line", required=True, select=True,
         ondelete='RESTRICT')
     quantity = fields.Float(
-        "Quantity", digits=(16, Eval('unit_digits', 2)),
+        "Quantity", digits=(16, Eval('unit_digits', 2)), required=True,
         depends=['unit_digits'])
     unit_digits = fields.Function(
         fields.Integer("Unit Digits"), 'on_change_with_unit_digits')

view/subscription_line_consumption_form.xml

@@ -6,6 +6,8 @@ this repository contains the full copyright notices and license terms. -->
     <field name="line"/>
     <label name="date"/>
     <field name="date"/>
+    <label name="quantity"/>
+    <field name="quantity"/>
     <label name="invoice_line"/>
     <field name="invoice_line"/>
 </form>

view/subscription_line_consumption_list.xml

@@ -4,5 +4,6 @@ this repository contains the full copyright notices and license terms. -->
 <tree>
     <field name="line" expand="1"/>
     <field name="date"/>
+    <field name="quantity"/>
     <field name="invoice_line" expand="1"/>
 </tree>