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/views/Overview/Overview.vue b/src/views/Overview/Overview.vue
index d999be4..2bf4205 100644
--- a/src/views/Overview/Overview.vue
+++ b/src/views/Overview/Overview.vue
@@ -37,6 +37,7 @@
 import OverviewServer from './OverviewServer';
 import PageSection from '@/components/Global/PageSection';
 import PageTitle from '@/components/Global/PageTitle';
+import { useI18n } from 'vue-i18n';
 
 export default {
   name: 'Overview',
@@ -55,6 +56,7 @@
   mixins: [LoadingBarMixin],
   data() {
     return {
+      $t: useI18n().t,
       showDumps: process.env.VUE_APP_ENV_NAME === 'ibm',
     };
   },