WIP: Add RAVEN VOEvent variant

• Add new fields to the VOEvent model here
• Add processing of these fields to the superevents API here, including validation
• Add processing and validation of these fields to the events API here
• Add new fields to the VOEvent files here
• Determine which external event needs to be included in the VOEvent
• Load in external event

gracedb/annotations/voevent_utils.py

@@ -60,6 +60,7 @@ def construct_voevent_file(obj, voevent, request=None):
         obj_is_superevent = True
         event = obj.preferred_event
         graceid = obj.default_superevent_id
+        # ext_event = obj.em_events ???
         obj_view_name = "superevents:view"
         fits_view_name = "api:default:superevents:superevent-file-detail"
     else:
@@ -286,7+287,7 @@
             )
             p_search.Description = "Specific low-latency search"
             v.What.append(p_search)
 
     # initial and update VOEvents must have a skymap.
     # new feature (10/24/2016): preliminary VOEvents can have a skymap,
     # but they don't have to.
@@ -316,7+317,7 @@
 
         ### Add to What
         v.What.append(skymap_group)
 
     ## Analysis specific attributes
     if voevent_type != 'retraction':
         ### Classification group (EM-Bright params; CBC only)