Accept agent type in more places (#4829)

* Accept agenttype in more places

* remove type hint

python/packages/autogen-core/src/autogen_core/_default_subscription.py

@@ -1,5 +1,6 @@
 from typing import Callable, Type, TypeVar, overload
 
+from ._agent_type import AgentType
 from ._base_agent import BaseAgent, subscription_factory
 from ._subscription_context import SubscriptionInstantiationContext
 from ._type_subscription import TypeSubscription
@@ -16,7 +17,7 @@ class DefaultSubscription(TypeSubscription):
         agent_type (str, optional): The agent type to use for the subscription. Defaults to None, in which case it will attempt to detect the agent type based on the instantiation context.
     """
 
-    def __init__(self, topic_type: str = "default", agent_type: str | None = None):
+    def __init__(self, topic_type: str = "default", agent_type: str | AgentType | None = None):
         if agent_type is None:
             try:
                 agent_type = SubscriptionInstantiationContext.agent_type().type

python/packages/autogen-core/src/autogen_core/_type_prefix_subscription.py

@@ -1,6 +1,7 @@
 import uuid
 
 from ._agent_id import AgentId
+from ._agent_type import AgentType
 from ._subscription import Subscription
 from ._topic import TopicId
 from .exceptions import CantHandleException
@@ -30,9 +31,12 @@ class TypePrefixSubscription(Subscription):
         agent_type (str): Agent type to handle this subscription
     """
 
-    def __init__(self, topic_type_prefix: str, agent_type: str):
+    def __init__(self, topic_type_prefix: str, agent_type: str | AgentType):
         self._topic_type_prefix = topic_type_prefix
-        self._agent_type = agent_type
+        if isinstance(agent_type, AgentType):
+            self._agent_type = agent_type.type
+        else:
+            self._agent_type = agent_type
         self._id = str(uuid.uuid4())
 
     @property

python/packages/autogen-core/src/autogen_core/_type_subscription.py

@@ -1,6 +1,7 @@
 import uuid
 
 from ._agent_id import AgentId
+from ._agent_type import AgentType
 from ._subscription import Subscription
 from ._topic import TopicId
 from .exceptions import CantHandleException
@@ -29,9 +30,12 @@ class TypeSubscription(Subscription):
         agent_type (str): Agent type to handle this subscription
     """
 
-    def __init__(self, topic_type: str, agent_type: str):
+    def __init__(self, topic_type: str, agent_type: str | AgentType):
         self._topic_type = topic_type
-        self._agent_type = agent_type
+        if isinstance(agent_type, AgentType):
+            self._agent_type = agent_type.type
+        else:
+            self._agent_type = agent_type
         self._id = str(uuid.uuid4())
 
     @property