Add ability to force validation for GH requests on revalidation

Reported in eclipsefdn/helpdesk#3921 (closed), there is an edge case where on initial validation of a new change set, the call to update the status in Github fails and crashes the workflow. While there is logic to recover in most cases, the case where the data is validated internally but was not updated remotely was not covered by the initial recovery logic. A new flag should be added so that we can force validation to complete even when there are no visible changes to compensate for this.