Record Support in DynamoDBContext

### Describe the feature

Currently `DynamoDBContext` supports class types for the object model type parameter but does not seem to work with record types. It would be great if it would support record types as well.

### Use Case

Using record types with DynamoDBContext.

### 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

### AWS .NET SDK and/or Package version used

AWSSDK.DynamoDBv2

### Targeted .NET Platform

.NET 6 and up

### Operating System and version

Any

Start by inspecting DynamoDBContext's handling of class types and the object model type parameter in the AWS SDK for .NET. Reproduce the reported behavior with a .NET 6 record type, then determine the expected support and verify that record types can be used with DynamoDBContext without breaking existing class support.

Written by the indexing model from the issue text.