gr-error-manager is introduced to deal with error events
fired from gr-rest-api-interface. Currently it will display
the first error it sees for 5 seconds, ignoring others during
that time. If a response comes back as a 403, it prompts the
user to refresh the page and the alert remains on the screen
indefinitely.
Bug: Issue 3992
Bug: Issue 3953
Change-Id: I4a54eb1e865b88f9a5531e864e0b1d58d638a4cd