Add collection data source to page

packages/core/src/pages/model/Page.ts

@@ -6,6 +6,7 @@ import ComponentWrapper from '../../dom_components/model/ComponentWrapper';
 import EditorModel from '../../editor/model/Editor';
 import { CssRuleJSON } from '../../css_composer/model/CssRule';
 import { ComponentDefinition } from '../../dom_components/model/types';
+import { DataCollectionStateMap } from '../../data_sources/model/data_collection/types';
 
 /** @private */
 export interface PageProperties {
@@ -38,6 +39,8 @@ export interface PagePropertiesDefined extends Pick<PageProperties, 'id' | 'name
 }
 
 export default class Page extends Model<PagePropertiesDefined> {
+  collectionsStateMap: DataCollectionStateMap = {};
+
   defaults() {
     return {
       name: '',