FactoryAggregate copying issue fix (ets-labs#220)

* Add test

* Implement deepcopy handler for FactoryAggregate provider

* Add more granularity for the test

* Update changelog

* Refactor test

Author: rmk135

docs/main/changelog.rst

@@ -9,6 +9,7 @@ follows `Semantic versioning`_
 
 Development version
 -------------------
+- Fix ``FactoryAggregate`` provider copying issue.
 - Regenerate C sources using Cython 0.29.7.
 
 3.14.5