Add git repository to a JuptyerLab App in Sagemaker Studio

### Product Version

- [ ] Amazon SageMaker Studio Classic
- [X] Amazon SageMaker Studio
- [ ] It is not related to SageMaker Studio

### Product Category

JupyterLab

### Description

I would like to have the ability to add a git repository to a JupyterLab App Instance in Sagemaker Studio like it is possible to add a git repository to a Notebook Instance in Sagemaker.
Somehow this feature for Notebook Instances is not available in Sagemaker Studio.

This is also reflected in the AWS CDK Documentation. It is possible to create git repository as a resource for Notebook instances where you can provide a secret to access the repository (see: https://docs.aws.amazon.com/cdk/api/v2/docs/aws-cdk-lib.aws_sagemaker.CfnCodeRepository.html)
but the same is not possible when adding it to a JuypterLab App in Sagemaker Studio, you can only add a URL to its settings as a property which doesn't seem to do a lot. (see: https://docs.aws.amazon.com/cdk/api/v2/docs/aws-cdk-lib.aws_sagemaker.CfnSpace.CodeRepositoryProperty.html)

### Other Details

_No response_

Start by reviewing the linked AWS CDK documentation for CfnCodeRepository and CfnSpace.CodeRepositoryProperty, then compare the repository capabilities for Notebook Instances and SageMaker Studio JupyterLab Apps. Done would require the requested repository-and-secret support to be available for a Studio JupyterLab App.

Written by the indexing model from the issue text.