REPP: Move Domains#Contacts to rails API format

app/controllers/repp/v1/domains/contacts_controller.rb

@@ -0,0 +1,39 @@
+module Repp
+  module V1
+    module Domains
+      class ContactsController < BaseController
+        before_action :set_current_contact, only: [:update]
+        before_action :set_new_contact, only: [:update]
+
+        def set_current_contact
+          @current_contact = current_user.registrar.contacts.find_by!(
+            code: params[:current_contact_id]
+          )
+        end
+
+        def set_new_contact
+          @new_contact = current_user.registrar.contacts.find_by!(code: params[:new_contact_id])
+        end
+
+        def update
+          @epp_errors << { code: '2304', msg: 'New contact must be valid' } if @new_contact.invalid?
+
+          if @new_contact == @current_contact
+            @epp_errors << { code: '2304', msg: 'New contact must be different from current' }
+          end
+
+          affected, skipped = TechDomainContact.replace(@current_contact, @new_contact)
+          data = { affected_domains: affected, skipped_domains: skipped }
+          render_success(data: data)
+        end
+
+        private
+
+        def contact_params
+          params.require(%i[current_contact_id new_contact_id])
+          params.permit(:current_contact_id, :new_contact_id)
+        end
+      end
+    end
+  end
+end