Distinguishing Between Streaming and Non-Streaming Events in TaskManager

Currently, when using the OnTaskCreated, OnMessageReceived, and OnTaskUpdated events of TaskManager, it's impossible to tell whether those were triggered by the streaming request or a non-streaming one. This is important for scenarios when users want to handle those by delegating the calls to the corresponding streaming or non-streaming APIs of the underlying LLM/Agent/SDK/Service.

Look at the TaskManager class and its event definitions (OnTaskCreated, OnMessageReceived, OnTaskUpdated). Identify where these events are triggered and examine the request context to determine if it's streaming or non-streaming. Add a property or parameter to the event args to indicate the request type. Check existing tests for TaskManager to see how events are tested and add new tests for the added property.

Written by the indexing model from the issue text.