[FIX] crm_partner_assign: minimum access rights to employee

Give the same as access rights to the employee as for the public user.
This patch is needed to allow a user to access the partner form.
Same for portal.
The list of grades in not a confidential information.

Fixes #7719

addons/crm_partner_assign/security/ir.model.access.csv

@@ -3,6 +3,8 @@ access_ crm_lead_report_assign,crm.lead.report.assign,model_crm_lead_report_assi
 access_ crm_lead_report_assign_all,crm.lead.report.assign.all,model_crm_lead_report_assign,base.group_user,1,0,0,0
 access_crm_partner_report,crm.partner.report.assign.all,model_crm_partner_report_assign,base.group_sale_salesman,1,0,0,0
 access_res_partner_grade,res.partner.grade,model_res_partner_grade,base.group_sale_salesman,1,1,1,0
+access_res_partner_grade_employee,res.partner.grade,model_res_partner_grade,base.group_user,1,0,0,0
+access_res_partner_grade_portal,res.partner.grade,model_res_partner_grade,base.group_portal,1,0,0,0
 access_res_partner_grade_public,res.partner.grade,model_res_partner_grade,base.group_public,1,0,0,0
 access_res_partner_grade_manager,res.partner.grade.manager,model_res_partner_grade,base.group_sale_manager,1,1,1,1
 access_res_partner_activation_user,res.partner.activation.user,model_res_partner_activation,base.group_user,1,0,0,0