add "related to" list for resources

We find at times the need to monitor usage on one device interface but show traffic information from another source.  For example, we may get a utilization alarm from the physical crossconnect on an external switch to the ISP, but we have no useful traffic data (or no data) on that switch.  The next step would be to go to traffic details on downstream devices, like firewalls.  It would be helpful to have a "Related To" URL list available to avoid manual navigation each time.  Ideally, this would be in the UI and available in alert tokens.