core&ui: add problem_config

Co-authored-by: undefined <i@undefined.moe>

packages/ui-default/components/problemconfig/reducer/index.ts

@@ -0,0 +1,11 @@
+import { combineReducers } from 'redux';
+import config from './config';
+import testdata from './testdata';
+
+const reducer = combineReducers({
+  config,
+  testdata,
+});
+
+export default reducer;
+export type RootState = ReturnType<typeof reducer>;