Start converting some enum-like strings to proper enums

data/callsign.py

@@ -1,5 +1,7 @@
 from dataclasses import dataclass
 
+from core.enums import LocationSourceForCallsign
+
 
 @dataclass
 class Callsign:
@@ -36,7 +38,7 @@ class Callsign:
     # ITU zone in which the callsign indicates they are operating
     itu_zone: int | None = None
     # Location source. This can be "HOME QTH" or "DXCC" depending on which provider gave us a location
-    location_source: str | None = None
+    location_source: LocationSourceForCallsign = LocationSourceForCallsign.NONE
 
     def fully_populated(self):
         """Utility method to indicate that the callsign data is fully populated. Multiple providers can return data for