.Net: Fix batch operation non-string keys with MongoDB (#13036)

### Motivation and Context

The ObjectID and Guid string support work in #12827 did not include
support for the method overloads that take an IEnumerable of keys. I
suspect this was due to merge/out of sync branches and was then missed
with the tests being disabled (they now pass).

### Description

Adds the support for Guid and ObjectID keys to the GetAsync, DeleteAsync
and UpdateAsync methods that take an IEnumerable.

### Contribution Checklist

<!-- Before submitting this PR, please make sure: -->

- [x] The code builds clean without any errors or warnings
- [x] The PR follows the [SK Contribution
Guidelines](https://github.com/microsoft/semantic-kernel/blob/main/CONTRIBUTING.md)
and the [pre-submission formatting
script](https://github.com/microsoft/semantic-kernel/blob/main/CONTRIBUTING.md#development-scripts)
raises no violations
- [x] All unit tests pass, and I have added new tests where possible
- [x] I didn't break anyone 😄

Author: damieng

dotnet/src/VectorData/MongoDB/MongoCollection.cs

@@ -171,9 +171,7 @@ public override async Task DeleteAsync(IEnumerable<TKey> keys, CancellationToken
     {
         Verify.NotNull(keys);
 
-        var stringKeys = keys is IEnumerable<string> k ? k : keys.Cast<string>();
-
-        await this.RunOperationAsync("DeleteMany", () => this._mongoCollection.DeleteManyAsync(this.GetFilterByIds(stringKeys), cancellationToken))
+        await this.RunOperationAsync("DeleteMany", () => this._mongoCollection.DeleteManyAsync(this.GetFilterByIds(keys), cancellationToken))
             .ConfigureAwait(false);
     }
 
@@ -220,10 +218,8 @@ public override async IAsyncEnumerable<TRecord> GetAsync(
             throw new NotSupportedException(VectorDataStrings.IncludeVectorsNotSupportedWithEmbeddingGeneration);
         }
 
-        var stringKeys = keys is IEnumerable<string> k ? k : keys.Cast<string>();
-
         using var cursor = await this
-            .FindAsync(this.GetFilterByIds(stringKeys), top: null, skip: null, includeVectors, sortDefinition: null, cancellationToken)
+            .FindAsync(this.GetFilterByIds(keys), top: null, skip: null, includeVectors, sortDefinition: null, cancellationToken)
             .ConfigureAwait(false);
 
         while (await cursor.MoveNextAsync(cancellationToken).ConfigureAwait(false))
@@ -270,14 +266,17 @@ private async Task UpsertCoreAsync(TRecord record, int recordIndex, IReadOnlyLis
         var replaceOptions = new ReplaceOptions { IsUpsert = true };
         var storageModel = this._mapper.MapFromDataToStorageModel(record, recordIndex, generatedEmbeddings);
 
-        var key = storageModel[MongoConstants.MongoReservedKeyPropertyName];
+        var key = GetStorageKey(storageModel);
 
         await this.RunOperationAsync(OperationName, async () =>
             await this._mongoCollection
                 .ReplaceOneAsync(this.GetFilterById(key), storageModel, replaceOptions, cancellationToken)
                 .ConfigureAwait(false)).ConfigureAwait(false);
     }
 
+    private static TKey GetStorageKey(BsonDocument document)
+        => (TKey)BsonTypeMapper.MapToDotNetValue(document[MongoConstants.MongoReservedKeyPropertyName]);
+
     private static async ValueTask<(IEnumerable<TRecord> records, IReadOnlyList<Embedding>?[]?)> ProcessEmbeddingsAsync(
         CollectionModel model,
         IEnumerable<TRecord> records,
@@ -676,11 +675,11 @@ private async IAsyncEnumerable<VectorSearchResult<TRecord>> EnumerateAndMapSearc
         }
     }
 
-    private FilterDefinition<BsonDocument> GetFilterById(object id)
-        => Builders<BsonDocument>.Filter.Eq(document => document[MongoConstants.MongoReservedKeyPropertyName], id);
+    private FilterDefinition<BsonDocument> GetFilterById(TKey id)
+        => Builders<BsonDocument>.Filter.Eq(MongoConstants.MongoReservedKeyPropertyName, id);
 
-    private FilterDefinition<BsonDocument> GetFilterByIds(IEnumerable<object> ids)
-        => Builders<BsonDocument>.Filter.In(document => document[MongoConstants.MongoReservedKeyPropertyName], ids);
+    private FilterDefinition<BsonDocument> GetFilterByIds(IEnumerable<TKey> ids)
+        => Builders<BsonDocument>.Filter.In(MongoConstants.MongoReservedKeyPropertyName, ids);
 
     private async Task<bool> InternalCollectionExistsAsync(CancellationToken cancellationToken)
     {