fix(init): Python init template's stack ID doesn't match other languages (#13480)

In other languages, if you create a directory `hello-cdk`, do `cdk init`, and then `cdk ls`, you get `HelloCdkStack`. In Python you get `hello-cdk`. Change the Python init template to match the other languages.

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*By submitting this pull request, I confirm that my contribution is made under the terms of the Apache-2.0 license*

Author: Jerry Kindall

packages/aws-cdk/lib/init-templates/v1/app/python/app.template.py

@@ -11,7 +11,7 @@
 from %name.PythonModule%.%name.PythonModule%_stack import %name.PascalCased%Stack
 
 
-app = cdk.App()
-%name.PascalCased%Stack(app, "%name.StackName%")
+app = core.App()
+%name.PascalCased%Stack(app, "%name.PascalCased%Stack")
 
 app.synth()

packages/aws-cdk/lib/init-templates/v2/app/python/app.template.py

@@ -6,6 +6,6 @@
 
 
 app = core.App()
-%name.PascalCased%Stack(app, "%name.StackName%")
+%name.PascalCased%Stack(app, "%name.PascalCased%Stack")
 
 app.synth()