[IMP] crm,website_crm_partner_assign: change some labels

In crm,website_crm_partner_assign and website_crm_score there were fields with
almost the same label, which was confusing, we change those names so it
reflects better what the field is used for.

|    field    |           module           |     old label    |         new label        |
------------------------------------------------------------------------------------------
| date_open   | crm                        | Assigned         | Assignation Date         |
| date_assign | website_crm_partner_assign | Assignation Date | Partner Assignation Date |
| assign_date | website_crm_score          | Assign Date      | Auto Assign Date         |
------------------------------------------------------------------------------------------

addons/crm/models/crm_lead.py

@@ -95,7 +95,7 @@ class Lead(models.Model):
     user_id = fields.Many2one('res.users', string='Salesperson', index=True, track_visibility='onchange', default=lambda self: self.env.user)
     referred = fields.Char('Referred By')
 
-    date_open = fields.Datetime('Assigned', readonly=True, default=fields.Datetime.now)
+    date_open = fields.Datetime('Assignation Date', readonly=True, default=fields.Datetime.now)
     day_open = fields.Float(compute='_compute_day_open', string='Days to Assign', store=True)
     day_close = fields.Float(compute='_compute_day_close', string='Days to Close', store=True)
     date_last_stage_update = fields.Datetime(string='Last Stage Update', index=True, default=fields.Datetime.now)

addons/website_crm_partner_assign/models/crm_lead.py

@@ -18,7 +18,7 @@ class CrmLead(models.Model):
         'lead_id',
         'partner_id',
         string='Partner not interested')
-    date_assign = fields.Date('Assignation Date', help="Last date this case was forwarded/assigned to a partner")
+    date_assign = fields.Date('Partner Assignation Date', help="Last date this case was forwarded/assigned to a partner")
 
     @api.multi
     def _merge_data(self, fields):