Add test runner extension: test your own extensions

[GermanCodeEngineer]

• A testing framework for PenguinMod: Test that blocks behaves as expected. Provides good error messages and error traceback.
• One can use this to test that PenguinMod projects, custom blocks or even extensions work. This is useful for bigger projects or when developing your own extensions.

[GermanCodeEngineer]

please dont merge yet, i still want to add a few typeof types

[GermanCodeEngineer]

now it's ready, I'd love feedback