Add a simple test for the new AWS::LanguageExtensions transform

[michael-k]

See https://aws.amazon.com/about-aws/whats-new/2022/09/aws-cloudformation-new-language-extensions-transform/

I've take the example from https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-languageextension-transform.html to see if that works.

At least the combination of AWS::LanguageExtensions with the AWS::Serverless transform and globals needs a bit of work. The globals checks don't work with multiple transforms. https://github.com/cloudtools/troposphere/blob/759496c4d2ed3fec6fcb7315b98fa9bf7e2335b2/troposphere/init.py#L834-L850

[michael-k]

The tests passed locally.

The failing spec test is a bit annoying. I've looked into it, but spent most of my available time understanding the code.

[markpeek]

Thanks!