feat: new field on order form for "promotion label"

Author: leomp12

src/views/resources/form/orders.html

@@ -213,6 +213,15 @@ <h4 class="i18n">
                 <input data-id="discount-coupon" type="text" class="form-control"
                   name="extra_discount.discount_coupon" />
               </div>
+
+              <div class="form-group">
+                <label class="i18n">
+                  <span data-lang="en_us">Promotion label</span>
+                  <span data-lang="pt_br">Rótulo da promoção</span>
+                </label>
+                <input data-id="discount-coupon" type="text" class="form-control"
+                  name="extra_discount.app.label" />
+              </div>
             </div>
           </div>