(aws_rds): Native support for Blue Green deployments of RDS via CDK

### Describe the feature

Raising this ticket to check if native support for a blue/green deployment of RDS will be added to CDK

### Use Case

Implementation of this feature that is available in RDS
https://docs.aws.amazon.com/AmazonRDS/latest/AuroraUserGuide/blue-green-deployments-creating.html

### Proposed Solution

_No response_

### Other Information

_No response_

### Acknowledgements

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

### CDK version used

NA

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

NA

Start with the AWS RDS blue/green deployments documentation linked in the issue and inspect the existing RDS constructs in the aws-cdk repository. The issue names no files, tests, API shape, or acceptance criteria, so clarify the intended CDK interface and supported RDS scenarios before implementation. Done should mean native CDK support is defined and covered by appropriate tests.

Written by the indexing model from the issue text.