[IMP] mrp_multi_level: enchance traceability with origin.

* keept description of planned orders verbose.
* make it translatable in most cases.
* while grouping demand include the product in the description.
* add `origin` field not mrp moves and planned orders. Fill it
  with top level demand origin.

mrp_multi_level/views/mrp_move_views.xml

@@ -34,6 +34,7 @@
                                 attrs="{'invisible':[('mrp_origin', '!=', 'mv')]}"
                             />
                             <field name="name" />
+                            <field name="origin" />
                         </group>
                         <group>
                             <field name="mrp_date" />

mrp_multi_level/views/mrp_planned_order_views.xml

@@ -8,6 +8,7 @@
         <field name="arch" type="xml">
             <tree decoration-info="fixed != True">
                 <field name="name" />
+                <field name="origin" />
                 <field name="product_mrp_area_id" />
                 <field name="product_id" />
                 <field name="mrp_area_id" />
@@ -76,6 +77,7 @@
         <field name="model">mrp.planned.order</field>
         <field name="arch" type="xml">
             <search>
+                <field name="origin" />
                 <field name="name" />
                 <field name="product_id" />
                 <field name="mrp_area_id" />