add more api endpoints

app/controllers/api/submitters_controller.rb

@@ -0,0 +1,13 @@
+# frozen_string_literal: true
+
+module Api
+  class SubmittersController < ApiBaseController
+    load_and_authorize_resource :submitter
+
+    def show
+      Submissions::EnsureResultGenerated.call(@submitter) if @submitter.completed_at?
+
+      render json: Submitters::SerializeForApi.call(@submitter, with_template: true, with_events: true)
+    end
+  end
+end