ENH: add resolve_value to Property

https://gitlab.com/caosdb/caosdb-pylib/-/merge_requests/64

unittests/test_apiutils.py

@@ -82,7 +82,8 @@ def test_resolve_reference():
     resolve_reference(prop)
     resolve_reference(prop_list)
     resolve_reference(prop_list2)
-    assert prop.value.id == db.Record(id=100).id
+    assert prop.value.id == 100
+    assert isinstance(prop.value, db.Entity) == True
 
     prop_list_ids = []
     for i in prop_list.value: