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/i18n.js b/src/i18n.js
index 8135a40..434ec10 100644
--- a/src/i18n.js
+++ b/src/i18n.js
@@ -21,7 +21,7 @@
   silentFallbackWarn: true,
   messages: loadLocaleMessages(),
   globalInjection: false,
-  legacy: true,
+  legacy: false,
 });
 
 export default i18n;