Keep messages a union of ctl and net (closed #1)

The messages array in the TwPacket class
is now planned to stay a Union of CtrlMessage and NetMessage.
Which both are empty duck typed classes. That abstract away
the 5 specific CtrlMessage classes and the many
game and system message classes.

```python
class CtrlMessage(Protocol):
    message_name: str
    def unpack(self, data: bytes) -> bool:
        ...
    def pack(self) -> bytes:
        ...

class NetMessage(Protocol):
    message_name: str
    system_message: bool
    header: ChunkHeader
    def unpack(self, data: bytes) -> bool:
        ...
    def pack(self) -> bytes:
        ...

class TwPacket(PrettyPrint):
    def __init__(self) -> None:
        self.messages: list[Union[CtrlMessage, NetMessage]] = []
```

twnet_parser/ctrl_message.py

@@ -0,0 +1,8 @@
+from typing import Protocol
+
+class CtrlMessage(Protocol):
+    message_name: str
+    def unpack(self, data: bytes) -> bool:
+        ...
+    def pack(self) -> bytes:
+        ...

twnet_parser/messages7/control/close.py

@@ -3,7 +3,6 @@ from typing import Optional
 from twnet_parser.pretty_print import PrettyPrint
 from twnet_parser.packer import Unpacker
 from twnet_parser.packer import pack_str
-from twnet_parser.chunk_header import ChunkHeader
 
 class CtrlClose(PrettyPrint):
     def __init__(
@@ -11,20 +10,6 @@ class CtrlClose(PrettyPrint):
             reason: Optional[str] = None
     ) -> None:
         self.message_name = 'close'
-        self.system_message = False
-        self.control_message = True
-        # TODO: do something about ChunkHeader
-        #       control messages do not really have a chunk header
-        #       but we need it here so we can duck type it into a
-        #       NetMessage
-        #       maybe it should be an optional field?
-        #       or there should be a union again instead of just
-        #       NetMessage
-        #
-        #       related issue
-        #       https://gitlab.com/teeworlds-network/twnet_parser/-/issues/1
-        self.header: ChunkHeader
-
         self.reason: Optional[str] = reason
 
     # first byte of data

twnet_parser/msg_matcher/control7.py

@@ -1,12 +1,12 @@
 from typing import Optional
 
 import twnet_parser.msg7
-from twnet_parser.net_message import NetMessage
+from twnet_parser.ctrl_message import CtrlMessage
 
 import twnet_parser.messages7.control.close as close7
 
-def match_control7(msg_id: int, data: bytes) -> NetMessage:
-    msg: Optional[NetMessage] = None
+def match_control7(msg_id: int, data: bytes) -> CtrlMessage:
+    msg: Optional[CtrlMessage] = None
 
     if msg_id == twnet_parser.msg7.CTRL_CLOSE:
         msg = close7.CtrlClose()

twnet_parser/packet.py

@@ -7,6 +7,7 @@ from twnet_parser import packer
 from twnet_parser.pretty_print import PrettyPrint
 from twnet_parser.message_parser import MessageParser
 from twnet_parser.net_message import NetMessage
+from twnet_parser.ctrl_message import CtrlMessage
 from twnet_parser.chunk_header import ChunkHeader, ChunkFlags
 from twnet_parser.msg_matcher.control7 import match_control7
 
@@ -24,10 +25,6 @@ CHUNKFLAG7_RESEND = 2
 
 PACKET_HEADER7_SIZE = 7
 
-class CtrlMessage(PrettyPrint):
-    def __init__(self, name: str) -> None:
-        self.message_name: str = name
-
 class PacketFlags7(PrettyPrint):
     def __init__(self):
         self.control = False
@@ -160,7 +157,7 @@ class PacketParser():
         pck.payload_raw = data[PACKET_HEADER7_SIZE:]
         pck.payload_decompressed = pck.payload_raw
         if pck.header.flags.control:
-            ctrl_msg: NetMessage = match_control7(data[7], data[8:])
+            ctrl_msg: CtrlMessage = match_control7(data[7], data[8:])
             pck.messages.append(ctrl_msg)
             return pck
         if pck.header.flags.compression: