aws-opensearch: Support Index State Management policies

### Describe the feature

It would be great if you would add support for creating/updating/removing [ISM (Index State Management)](https://docs.aws.amazon.com/opensearch-service/latest/developerguide/ism.html) policies for OpenSearch via CDK.

At the moment, the [only instructions](https://aws.amazon.com/blogs/big-data/automating-index-state-management-for-amazon-opensearch-service/) operate through the console, which is not ideal.

### Use Case

It would make sense to be able to completely configure an OpenSearch cluster via CDK. This is a missing feature.

### 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

2

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

MacOS Monterey 12.6.5

Start by reviewing the aws-opensearch CDK construct and the linked AWS ISM documentation. Define the supported create, update, and removal behavior for policies, then identify the construct tests that should demonstrate complete OpenSearch configuration through CDK.

Written by the indexing model from the issue text.