add config interface to theme shared testing module

npm/ng-packs/packages/theme-shared/testing/src/lib/models/config.ts

@@ -0,0 +1,5 @@
+import { Validation } from '@ngx-validate/core';
+
+export interface Config {
+  validation?: Partial<Validation.Config>;
+}

npm/ng-packs/packages/theme-shared/testing/src/lib/models/index.ts

@@ -0,0 +1 @@
+export * from './config';