A lot of work on event related modules. Also a lot of clean up.

app/models/event_session_models.py

@@ -100,6 +100,8 @@ class Event_Session_Base(BaseModel):
     event_track: Optional[Event_Track_Base]
     poc_event_person: Optional[Event_Person_Base] # NOTE: Using thi will probably create an import loop
 
+    proposal_json: Optional[Union[Json, None]]
+
     _processed_at: datetime.datetime = PrivateAttr(default_factory=datetime.datetime.now)
 
     #@validator('event_session_id_random', always=True)