Implement MongoDB-based storage for Pack Run approval, artifact, log, and state management

- Added MongoPackRunApprovalStore for managing approval states with MongoDB.
- Introduced MongoPackRunArtifactUploader for uploading and storing artifacts.
- Created MongoPackRunLogStore to handle logging of pack run events.
- Developed MongoPackRunStateStore for persisting and retrieving pack run states.
- Implemented unit tests for MongoDB stores to ensure correct functionality.
- Added MongoTaskRunnerTestContext for setting up MongoDB test environment.
- Enhanced PackRunStateFactory to correctly initialize state with gate reasons.

src/Concelier/StellaOps.Concelier.WebService/Contracts/AdvisoryChunkResponses.cs

@@ -0,0 +1,26 @@
+using System.Collections.Generic;
+
+namespace StellaOps.Concelier.WebService.Contracts;
+
+public sealed record AdvisoryChunkCollectionResponse(
+    string AdvisoryKey,
+    int Total,
+    bool Truncated,
+    IReadOnlyList<AdvisoryChunkItemResponse> Chunks,
+    IReadOnlyList<AdvisoryChunkSourceResponse> Sources);
+
+public sealed record AdvisoryChunkItemResponse(
+    string DocumentId,
+    string ChunkId,
+    string Section,
+    string ParagraphId,
+    string Text,
+    IReadOnlyDictionary<string, string> Metadata);
+
+public sealed record AdvisoryChunkSourceResponse(
+    string ObservationId,
+    string DocumentId,
+    string Format,
+    string Vendor,
+    string ContentHash,
+    DateTimeOffset CreatedAt);