Update tests for not found component

Author: ruiqi7

frontend/__mocks__/styleMock.ts

@@ -0,0 +1,3 @@
+const styleMock = {};
+
+export default styleMock;

frontend/jest.config.ts

@@ -90,7 +90,10 @@ const config: Config = {
   // ],
 
   // A map from regular expressions to module names or to arrays of module names that allow to stub out resources with a single module
-  // moduleNameMapper: {},
+  moduleNameMapper: {
+    '\\.(css)$': '<rootDir>/__mocks__/styleMock.ts',
+    '\\.(svg)$': '<rootDir>/__mocks__/styleMock.ts',
+  },
 
   // An array of regexp pattern strings, matched against all module paths before considered 'visible' to the module loader
   // modulePathIgnorePatterns: [],