(aws-timestream): (Add property for modifying Schema / Partition Key)

### Describe the feature

I need a way from CDK to set the Schema element of CfnTableProps to allow the custom partitioning to work the way I want. Currently, this isn't supported anywhere throughout the stack, including Cloud Formation Cfn* libraries meaning I have no clear options, not even by using L1 constructs. I am unsure how to work around this.

See https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-properties-timestream-table-schema.html for a description of what I mean.

### Use Case

There is not a clear way to work around this. The table property cannot be modified once the table is created, so you have to be able to do it here. The only workaround I can think of is to remove the tables from CDK entirely and create them by some external means.

### 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

2.89.0

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

Windows and Linux

Start with the aws-timestream CfnTableProps definition and the AWS CloudFormation Timestream table schema documentation linked in the issue. Trace how the table properties are exposed and synthesized, then verify that a custom Schema/partition key can be configured through CDK and produces the expected CloudFormation output.

Written by the indexing model from the issue text.