[APIV4] GET /users/{user_id}/status - user status endpoint for apiV4 (#5824)

i18n/en.json

@@ -2483,6 +2483,10 @@
     "id": "api.user.init.debug",
     "translation": "Initializing user API routes"
   },
+  {
+    "id": "api.status.init.debug",
+    "translation": "Initializing status API routes"
+  },
   {
     "id": "api.user.ldap_to_email.not_available.app_error",
     "translation": "AD/LDAP not available on this server"
@@ -2863,6 +2867,10 @@
     "id": "api.websocket_handler.invalid_param.app_error",
     "translation": "Invalid {{.Name}} parameter"
   },
+  {
+    "id": "api.status.user_not_found.app_error",
+    "translation": "User not found"
+  },
   {
     "id": "app.channel.create_channel.no_team_id.app_error",
     "translation": "Must specify the team ID to create a channel"