.Net: Bring back LibraryInfo for MongoClient lost in #f2df866

[damieng]

Motivation and Context

Previous versions of the MongoDB connector provided LibraryInfo on the client, see

semantic-kernel/dotnet/src/Connectors/Connectors.Memory.MongoDB/MongoDBMemoryStore.cs

Line 227 in 656159e

settings.LibraryInfo = new LibraryInfo("Microsoft Semantic Kernel", skVersion);

This was inadvertently removed in 656159e

Description

This change brings back the LibraryInfo and updates it from Microsoft Semantic Kernel to Microsoft.Extensions.VectorData

Contribution Checklist

• 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 😄