Definition of tasks with typed properties in .kraken.py fails with KeyError reading from sys.modules

[NiklasRosenstein]

When creating a Task subclass in a Kraken build script with typed properties, it fails to look up the scope of the build script in sys.modules as it is not a registered Python module.

The workaround atm. is to define the task in a Python module in build-support/ in the project root directory (natively supported by Kraken to load additional modules from).