Frontend separate login / credentials pages

This merge request adds two separate, static pages for logging in and verifying credentials. Logging in and confirming credentials is not handled in the existing app. This app is edited to work with these changes and start up on the preferences page

frontend/src/__mocks__/localStorage.js

-// Mocks window.localStorage
-// Retrieved from: https://github.com/facebook/jest/issues/2098
-// eslint-disable-next-line
-const localStorageMock = (function () {
-  let store = {};
-  return {
-    getItem(key) {
-      return store[key];
-    },
-    setItem(key, value) {
-      store[key] = value.toString();
-    },
-    clear() {
-      store = {};
-    },
-    removeItem(key) {
-      delete store[key];
-    },
-  };
-}());
-
-Object.defineProperty(window, 'localStorage', { value: localStorageMock });