add subjects and reviwers query

app/graphql/resolvers/subjects_query_resolver.rb

@@ -0,0 +1,12 @@
+# frozen_string_literal: true
+module Resolvers
+  class SubjectsQueryResolver
+    def initialize(context)
+      @context = context
+    end
+
+    def resolve
+      SubjectPolicy::Scope.new(@context[:current_user], Subject).resolve
+    end
+  end
+end