(aws_cdk.aws_lambda_python_alpha): Allow creating of Command Hooks

### Describe the feature

Allow running pre-bundling install of extra dependencies in an image such as poetry-export-plugin required for Poetry 2+.

### Use Case

Allow use of poetry 2+

### Proposed Solution

Allow creation of the interface subclasses and serialization to typescipt.

### Other Information

_No response_

### Acknowledgements

- [ ] I may be able to implement this feature request
- [ ] This feature might incur a breaking change

### AWS CDK Library version (aws-cdk-lib)

2.220.0

### AWS CDK CLI version

2.1030.0

### Environment details (OS name and version, etc.)

Linux Ubuntu 22.04

Start in the aws_cdk.aws_lambda_python_alpha component and inspect how bundling interfaces are defined and serialized to TypeScript. Trace the existing dependency-install flow; done means callers can create command-hook interface subclasses that run pre-bundling installs in the image, supporting Poetry 2+.

Written by the indexing model from the issue text.