Add Observability to Data Model Operations is DynamoDB HLL

[96malhar]

Description

This PR adds observability to Data Model operations is DynamoDB HLL by creating traces using the SDK observability APIs.

• Traces are only created for public APIs that make a network call.
• I have updated the Async public APIs to await the Task instead of returning it. This is done to ensure that the trace is not disposed before the function completes its execution.

Motivation and Context

This change is required as part of the Observability initiative for the SDK and HLLs
DOTNET-7679

Testing

• All existing Unit and Integrations tests pass locally
• Pending a full dry-run. Since I am targeting a feature branch, I'll perform a full dry run on the feature branch itself after observability updates are merged in for both the data model and document model operations

Screenshots (if appropriate)

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist

• My code follows the code style of this project
• My change requires a change to the documentation
• I have updated the documentation accordingly
• I have read the README document
• I have added tests to cover my changes
• All new and existing tests passed

License

• I confirm that this pull request can be released under the Apache 2 license