Remove Purchase prefix to purchase request menu entry

This create a simpler title for the tab.

modules/purchase_request/doc/design.rst

@@ -23,9 +23,9 @@ either done or gets cancelled.
 
    Purchase Requests can be found by opening the main menu item:
 
-      |Purchases --> Purchase Requests|__
+      |Purchases --> Requests|__
 
-      .. |Purchases --> Purchase Requests| replace:: :menuselection:`Purchases --> Purchase Requests`
+      .. |Purchases --> Requests| replace:: :menuselection:`Purchases --> Requests`
       __ https://demo.tryton.org/model/purchase.request
 
 Wizards

modules/purchase_request/purchase_request.xml

@@ -26,7 +26,7 @@ this repository contains the full copyright notices and license terms. -->
         </record>
 
         <record model="ir.action.act_window" id="act_purchase_request_form">
-            <field name="name">Purchase Requests</field>
+            <field name="name">Requests</field>
             <field name="res_model">purchase.request</field>
         </record>
         <record model="ir.action.act_window.view"