Added Session to the __init__ file, and changed docs and test accordingly

src/meshctrl/exceptions.py

@@ -22,9 +22,6 @@ class FileTransferError(MeshCtrlError):
 
     Attributes:
         stats (dict): {"result" (str): Human readable result, "size" (int): number of bytes successfully transferred}
-        initialized (asyncio.Event): Event marking if the Session initialization has finished. Wait on this to wait for a connection.
-        alive (bool): Whether the session connection is currently alive
-        closed (asyncio.Event): Event that occurs when the session closes permanently
     """
     def __init__(self, message, stats):
         self.stats = stats