Allow fast ObjectType creation based on dataclasses (#1157)

* Allow fast ObjectType creation based on dataclasses

* Fixed Python 3.8 integration

* Added repr and eq methods to ObjectType containers

* Reformatted code

* Fixed mypy issue

* Removed unused __init__ for ObjectType containers

* Use black in dataclasses

* Use latest black verison on precommit

Author: syrusakbary