Add Adapter.set_segments() and use it when refreshig the segment

This makes the internal API a bit more consistent

src/wagtail_personalisation/wagtail_hooks.py

@@ -74,7 +74,7 @@ def serve_variation(page, request, serve_args, serve_kwargs):
     user_segments = []
     adapter = get_segment_adapter(request)
 
-    for segment in adapter.get_all_segments():
+    for segment in adapter.get_segments():
         try:
             user_segment = Segment.objects.get(
                 pk=segment['id'], status=Segment.STATUS_ENABLED)