remove NodeJsFunction constructs from library

[kaizencc]

If we ever want to move this library into aws-cdk-lib, we cannot depend on experimental constructs. We will have to figure out a different way to bundle assets and refactor the two custom resource lambdas that currently utilize NodeJsFunction.

[SamStephens]

Unless I'm missing something, NodeJsFunction is no longer experimental; it carries the Stable banner now.

https://github.com/aws/aws-cdk/tree/e9b07a7b32f4b6798f07a4e8012bfc5b435c4f49/packages/%40aws-cdk/aws-lambda-nodejs