feat: refactor navigation to comply with vuejs/rfcs#150

feat: refactor navigation to comply with vuejs/rfcs#150

BREAKING CHANGE: This follows the RFC at https://github.com/vuejs/rfcs/pull/150
  Summary: `router.afterEach` and `router.onError` are now the global equivalent of
  `router.push`/`router.replace` as well as navigation through the interface
  (`history.go()`). A navigation only rejects if there was an unexpected error.
  A navigation failure will still resolve the promise returned by `router.push`
  and be exposed as the resolved value.