Add DynamoDBEvents SDK Convertor package

[irina-herciu]

Issue #, if available: #1657

Description of changes:

• Addition of DynamoDBEvents SDK Converter Package: Implements converters that transform raw DynamoDB event data into .NET classes, enhancing developer experience by providing a more intuitive object model.
• Unit Tests: Includes comprehensive unit tests to ensure the reliability and correctness of the conversion logic.
• Documentation Updates: Adds usage examples and API documentation to guide developers in integrating the new converters into their Lambda function

Java’s DynamodbAttributeValueTransformer provides a similar solution. The .NET SDK does not have a native implementation, but this extension library can achieve feature parity.

ConvertToSdkAttribute: Converts DynamoDBEvent.AttributeValue to Amazon.DynamoDBv2.Model.AttributeValue.
ConvertToSdkAttributeValueDictionary: Converts a dictionary of Lambda attributes to SDK attributes.
ConvertToSdkIdentity: Converts DynamoDBEvent.Identity to Amazon.DynamoDBv2.Model.Identity.
ConvertToSdkStreamRecord: Converts DynamoDBEvent.StreamRecord to Amazon.DynamoDBv2.Model.StreamRecord.

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.