.NET: [BREAKING] Rename from ServiceStoredSimulatingChatClient to PerServiceCallChatHistoryPersistingChatClient (#4993)

* Rename from ServiceStoredSimulatingChatClient to PerServiceCallChatHistoryPersistingChatClient

* Address PR comment

dotnet/samples/02-agents/Agents/Agent_Step19_InFunctionLoopCheckpointing/Program.cs

@@ -1,7 +1,7 @@
 // Copyright (c) Microsoft. All rights reserved.
 
 // This sample demonstrates how the ChatClientAgent persists chat history after each individual
-// call to the AI service, using the SimulateServiceStoredChatHistory option.
+// call to the AI service, using the RequirePerServiceCallChatHistoryPersistence option.
 // When an agent uses tools, FunctionInvokingChatClient may loop multiple times
 // (service call → tool execution → service call), and intermediate messages (tool calls and
 // results) are persisted after each service call. This allows you to inspect or recover them
@@ -9,7 +9,7 @@
 // yet finalized (e.g., tool calls without results) being persisted, which may be undesirable in some cases.
 //
 // To use end-of-run persistence instead (atomic run semantics), remove the
-// SimulateServiceStoredChatHistory = true setting (or set it to false). End-of-run
+// RequirePerServiceCallChatHistoryPersistence = true setting (or set it to false). End-of-run
 // persistence is the default behavior.
 //
 // The sample runs two multi-turn conversations: one using non-streaming (RunAsync) and one
@@ -54,7 +54,7 @@ static string GetTime([Description("The city name.")] string city) =>
         _ => $"{city}: time data not available."
     };
 
-// Create the agent — per-service-call persistence is enabled via SimulateServiceStoredChatHistory.
+// Create the agent — per-service-call persistence is enabled via RequirePerServiceCallChatHistoryPersistence.
 // The in-memory ChatHistoryProvider is used by default when the service does not require service stored chat
 // history, so for those cases, we can inspect the chat history via session.TryGetInMemoryChatHistory().
 IChatClient chatClient = string.Equals(store, "TRUE", StringComparison.OrdinalIgnoreCase) ?
@@ -64,7 +64,7 @@ AIAgent agent = chatClient.AsAIAgent(
     new ChatClientAgentOptions
     {
         Name = "WeatherAssistant",
-        SimulateServiceStoredChatHistory = true,
+        RequirePerServiceCallChatHistoryPersistence = true,
         ChatOptions = new()
         {
             Instructions = "You are a helpful assistant. When asked about multiple cities, call the appropriate tool for each city.",