i18n, vue-router and vuex upgrade

1. Configuration of i18n legacy as false.
2. Translation function t is called using the useI18n.
3. Used the i18n.global.t() function from i18n instead of this.$t()
4. Event bus error that occurred during logout.
5. Implemented vue-router 4.4.0 and vuex upgrade to 4.1.0

Change-Id: I9464d82c76dcc1445ce271983ea3ab9d7b03d265
Signed-off-by: Surya Venkatesan <suryav@ami.com>
diff --git a/src/components/AppNavigation/AppNavigation.vue b/src/components/AppNavigation/AppNavigation.vue
index 4c93be5..eb8c2c6 100644
--- a/src/components/AppNavigation/AppNavigation.vue
+++ b/src/components/AppNavigation/AppNavigation.vue
@@ -60,12 +60,14 @@
 //Exact match alias set to support
 //dotenv customizations.
 import AppNavigationMixin from './AppNavigationMixin';
+import { useI18n } from 'vue-i18n';
 
 export default {
   name: 'AppNavigation',
   mixins: [AppNavigationMixin],
   data() {
     return {
+      $t: useI18n().t,
       isNavigationOpen: false,
       currentUserRole: null,
     };