Translate JS code in listings and forms

assets/js/src/form/form.jsx

@@ -167,7 +167,7 @@ define(
             <input
               className="button button-primary"
               type="submit"
-              value="Save"
+              value={MailPoet.I18n.t('save')}
               disabled={this.state.loading} />
           );
         }
@@ -199,4 +199,4 @@ define(
 
     return Form;
   }
-);
+);