se#481 #161  Create method `get_category_descendants` (#160)
se#481 #161  Create method `get_category_descendants` (#160)

* #481  Create new method

* #161  Move `ProductActiveManager` from SE to `catalog` app

* se#481  Add missed type annotations

fidals/refarm-site,fidals/refarm-site,fidals/refarm-site