Refactor/dumper (#234)

* refactor dumper

* fix typing

* codestyle

* bug fix

* bug fix

* fix catboost dumping

Author: voorhs

autointent/_dump_tools.py

@@ -0,0 +1,4 @@
+from .main import Dumper
+from .unit_dumpers import PydanticModelDumper
+
+__all__ = ["Dumper", "PydanticModelDumper"]