Fix multiple saving requests when save button clicked multiple times

[MAILPOET-2450]

assets/js/src/form_editor/store/actions.jsx

@@ -44,10 +44,10 @@ export function removeNotice(id) {
 }
 
 export function* saveForm() {
-  yield {
-    type: 'SAVE_FORM_STARTED',
-  };
   yield {
     type: 'SAVE_FORM',
   };
+  yield {
+    type: 'SAVE_FORM_STARTED',
+  };
 }

assets/js/src/form_editor/store/controls.jsx

@@ -3,6 +3,9 @@ import MailPoet from 'mailpoet';
 
 export default {
   SAVE_FORM() {
+    if (select('mailpoet-form-editor').getIsFormSaving()) {
+      return;
+    }
     const formData = select('mailpoet-form-editor').getFormData();
     dispatch('mailpoet-form-editor').removeNotice('save-form');
     MailPoet.Ajax.post({