Enhanced app with Azure AI and vector search

- Modified `ApplicationDbContext.cs` to correct the `.IsVector()` method placement for `DocumentChunk`.
- Removed `MemoryResponse.cs` class, indicating a move away from this model.
- Enhanced `Program.cs` with Azure AI services integration for text embeddings and chat completions. Updated OpenAPI descriptions and reintroduced `/api/ask` with vector search.
- Adjusted `ChatService.cs` to improve question-asking functionality using document chunks.
- Updated `VectorSearchService.cs` with a new `AskQuestionAsync` method for advanced search and response capabilities. Made `GetContentAsync` static.
- Formatted `SqlDatabaseVectorSearch.csproj` and managed NuGet package inclusions.
- Simplified `appsettings.json` by removing unused keys.
- Added a new `Response` record class for standardized service responses.

SqlDatabaseVectorSearch/appsettings.json

@@ -18,10 +18,7 @@
     },
     "AppSettings": {
         "MessageLimit": 20,
-        "MessageExpiration": "00:05:00",
-        "StoragePath": "",
-        "VectorDbPath": "",
-        "QueuePath": ""
+        "MessageExpiration": "00:05:00"
     },
     "Logging": {
         "LogLevel": {