Renamed unit test from Bulk to LoadTesting

This is more descriptive, consistent with other similar methods, and is aligned with the existing comment header.

Author: JeremyCaney

OnTopic.Tests/TopicMappingServiceTest.cs

@@ -86,7 +86,7 @@ public TopicMappingServiceTest(TopicInfrastructureFixture<StubTopicRepository> f
     ///   </para>
     /// </remarks>
     [Fact]
-    public async Task Map_Bulk_EvaluateThreshold() {
+    public async Task Map_LoadTesting_EvaluateThreshold() {
 
       /*------------------------------------------------------------------------------------------------------------------------
       | Establish variables