add AWS CDK Toolkit (cdk command) to Lambda images

[leonjohan3]

AWS Tools like aws cli, kubectl, ecs-cli, eksctl, etc. is installed in the Lambda Images, could we also install cdk ?

e.g. https://github.com/aws/aws-codebuild-docker-images/blob/master/al-lambda/aarch64/corretto21/Dockerfile#L74

AWS CDK Toolkit (cdk command): https://docs.aws.amazon.com/cdk/v2/guide/ref-cli-cmd.html

[polothy]

Potential problem is that CDK releases often (weekly'ish) and if your CDK lib version in your program is higher than the CLI, the CLI wont synth your app. So, you will likely end up always trying to upgrade it unless CodeBuild updates their images more often than I thought.