Bugfix: fix navigation rendering

-  ADD_NAV_ITEM mutation now gets copied instead of referenced to trigger a state change.
-  applicationsList navItem item needs a copy instead of mutating the base item
-  check for route.path instead of route name in ADD_NAV_ITEM which can change over time

https://github.com/owncloud/ocis/issues/1031
https://github.com/owncloud/phoenix/pull/4430
https://github.com/owncloud/ocis/issues/1043
