Store: Hide extraOptions in byKey's TypeScript definition (T1169878) (#594)

Author: OlegKipchatov

js/dx.aspnet.data.d.ts

@@ -1,4 +1,4 @@
-import CustomStore from "devextreme/data/custom_store";
+import DxCustomStore from "devextreme/data/custom_store";
 
 interface Options {
     key?: string|Array<string>,
@@ -41,4 +41,8 @@ interface Options {
     onPush?: (changes: Array<any>) => void;
 }
 
+declare class CustomStore extends DxCustomStore {
+    byKey(key: any | string | number): any;
+}
+
 export function createStore(options: Options): CustomStore;