AWS::CloudFormation::Init dynamic-references

Quick Sample Summary:
1. Title -> AWS::CloudFormation::Init dynamic-references
2. Scope of request -> Use of Dynamic referencing in UserData ( Instance resource) and aws::cloudformation::init currently is not supported

Dynamic referencing allows resolution of secrets ( via secretsmanager ) or parameters ( via parameters store) in cloud formation, which will in-turn discontinue the practice of putting secrets in plain text in CloudFormation templates (https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/dynamic-references.html)

3. Expected behavior -> Dynamic referencing inside AWS::CloudFormation::Init should resolve secrets .
4. Test case recommendation (optional) -> it should help me do X given existing Y (if applicable); it should/shouldn't change Z.
5. Links to existing API doc (optional) -> Updated API docs at https://example.com/api-new.html
6. Category tag (optional) -> Compute
7. Any additional context (optional)

Start with the linked AWS dynamic references documentation and compare its supported behavior with the issue's UserData and AWS::CloudFormation::Init scope. Done means dynamic references resolve secrets or parameter values in AWS::CloudFormation::Init and UserData without requiring plaintext secrets in the template.

Written by the indexing model from the issue text.