Implement keyboard navigation using arrow keys in the whole application. (#2)

Reviewed-on: #2

frontend/int/forward/main.js

@@ -1,5 +1,7 @@
 import { createApp } from 'vue'
 import App from './RestrictedForward.vue'
 import '@/assets/style.css'
+import { initKeyboardNavigation } from '@/utils/keynav'
 
 createApp(App).mount('#app')
+initKeyboardNavigation()

frontend/int/reset/main.js

@@ -1,5 +1,7 @@
 import { createApp } from 'vue'
 import ResetApp from './ResetApp.vue'
 import '@/assets/style.css'
+import { initKeyboardNavigation } from '@/utils/keynav'
 
 createApp(ResetApp).mount('#app')
+initKeyboardNavigation()