updates how Client handles (re-)connection with the server

The client will update the proxy class serialization directly on the
ProxyClass instance. this is the only time this get "updated".
Now, the client also notifies the observers directly with the proxy
object as this the serialization of the proxy class is now done through
its `serialize` method (which we have overwritten in a previous commit).

src/pydase/client/client.py

@@ -2,7 +2,7 @@ import asyncio
 import logging
 import sys
 import threading
-from typing import TypedDict, cast
+from typing import TYPE_CHECKING, TypedDict, cast
 
 import socketio  # type: ignore
 
@@ -121,7 +121,13 @@ class Client:
             self.proxy, serialized_object=serialized_object
         )
         serialized_object["type"] = "DeviceConnection"
-        self.proxy._notify_changed("", loads(serialized_object))
+        if self.proxy._service_representation is not None:
+            # need to use object.__setattr__ to not trigger an observer notification
+            object.__setattr__(self.proxy, "_service_representation", serialized_object)
+
+            if TYPE_CHECKING:
+                self.proxy._service_representation = serialized_object  # type: ignore
+        self.proxy._notify_changed("", self.proxy)
         self.proxy._connected = True
 
     async def _handle_disconnect(self) -> None: