[IMP] crm: Change the priority labels on lead/opportunities

Relabel priority values like this::

   Low = no star
   Medium = 1 star
   High = 2 stars
   Very high = 3 stars

Task Id: 1827293

addons/crm/models/crm_stage.py

@@ -4,8 +4,8 @@
 from odoo import api, fields, models
 
 AVAILABLE_PRIORITIES = [
-    ('0', 'Normal'),
-    ('1', 'Low'),
+    ('0', 'Low'),
+    ('1', 'Medium'),
     ('2', 'High'),
     ('3', 'Very High'),
 ]