AWS Doc DB: Global AWS document DB support

### Describe the feature

Currently using CDK we can only create regional AWS document DBs. Whereas AWS CLI provides the feature of creating document DB global clusters as well. Can we have a similar feature via CDK like what we today have for Aurora RDS global clusters.

### Use Case

Creating AWS document DB in multiple regions with cross-region replication.

### Proposed Solution

Having below parameters in CfnDBCluster for DocDB

/**
* If you are configuring an global database cluster and want your Document DB cluster to be a secondary member in the global database cluster, specify the global cluster ID of the global database cluster.
*/
globalClusterIdentifier?: string;

/**
* The AWS Region which contains the source DB cluster when replicating a DB cluster. For example, `us-east-1` .
*/
sourceRegion?: string;

### 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.)

Any

Start by examining the existing Aurora RDS global-cluster support and the CfnDBCluster entry point for DocumentDB. Compare the available CloudFormation properties with the proposed globalClusterIdentifier and sourceRegion parameters. Done means CDK can express DocumentDB global-cluster members across regions with the requested properties.

Written by the indexing model from the issue text.