feat: sla 1 - refactor sla_policies model and add applied_sla model (#8602)

* feat: add models

* chore: refactor sla column names

* chore: remove foreign keys

* chore: fix spec

* chore: refactor models

enterprise/app/controllers/api/v1/accounts/sla_policies_controller.rb

@@ -22,7 +22,8 @@ class Api::V1::Accounts::SlaPoliciesController < Api::V1::Accounts::EnterpriseAc
   end
 
   def permitted_params
-    params.require(:sla_policy).permit(:name, :rt_threshold, :frt_threshold, :only_during_business_hours)
+    params.require(:sla_policy).permit(:name, :description, :first_response_time_threshold, :next_response_time_threshold,
+                                       :resolution_time_threshold, :only_during_business_hours)
   end
 
   def fetch_sla