Run `aws-cdk-lib.cloudformation_include` test library

[Momo Kornher]

The cloudformation_include module contains a vast library of templates, asserting inputTemplate == outputTemplate, as well as some invalid templates.

https://github.com/aws/aws-cdk/tree/ad4f799611e648166b5fda9f6c543d1aca9b6a26/packages/%40aws-cdk/cloudformation-include/test/test-templates

We should find a way to run this test library against deCDK as well.