.Net: .Net: Added AstraDB memory store connector

[hakeemsyd]

Motivation and Context

We are going to add Astra as a memory store.

DataStax Astra DB is a serverless vector database that’s perfect for managing mission-critical AI workloads. It’s built on Apache Cassandra®, making Astra DB a highly scalable, reliable database technology. It’s a powerful all-in-one data storage solution, ideal for Generative AI projects.

Description

• Add AstraDB connector for dotnet memory connectors.
• Add integration tests for that AstraDB memory connector

Contribution Checklist

• [x] The code builds clean without any errors or warnings
• [ ] The PR follows the SK Contribution Guidelines and the pre-submission formatting script raises no violations
• [ ] All unit tests pass, and I have added new tests where possible
• [ ] I didn't break anyone :smile:

[markwallace-microsoft]

@hakeemsyd We are in the process of updating our memory connector design, the Memory ADR is here: https://github.com/microsoft/semantic-kernel/issues/5887. Here is an example PR which migrates an existing connector to the new design: https://github.com/microsoft/semantic-kernel/pull/8065.

The old design is going to be made obsolete and eventually removed.

Here's how I propose we proceed with this PR:

1. We will create a feature branch for the new connector
2. Change this PR to target the feature branch
3. Create a new PR which adds the implementation of the new design (again targeting the new feature branch)
4. Merge to main once all of the implementation and tests have been completed

Would you be interested in contributing an implementation using the new design?

[hakeemsyd]

@hakeemsyd We are in the process of updating our memory connector design, the Memory ADR is here: #5887. Here is an example PR which migrates an existing connector to the new design: #8065.

The old design is going to be made obsolete and eventually removed.

Here's how I propose we proceed with this PR:

1. We will create a feature branch for the new connector
2. Change this PR to target the feature branch
3. Create a new PR which adds the implementation of the new design (again targeting the new feature branch)
4. Merge to main once all of the implementation and tests have been completed

Would you be interested in contributing an implementation using the new design?

@markwallace-microsoft, yeah sure, I will update the connector implementation using the new design. Please let me know which feature branch I should target once it’s ready.

[markwallace-microsoft]

@hakeemsyd we have recently announced a new Microsoft.Extensions.VectorData.Abstractions package which we have developed in partnership with the .NET team. We have also started migrating our memory connectors to use these new abstractions and plan to obsolete the old implementations. So we are not taking any new changes to the older memory connectors. If you are interested in contributing am AstraDB memory connector using the new memory abstractions we would consider adding this to the Semantic Kernel.