Multiplayer saved games

Enables to save multiplayer games.
When the savegame is loaded, the settings are frozen (except the non-AI-player assignment settings).

source/network/NetMessages.h

@@ -1,4 +1,4 @@
-/* Copyright (C) 2021 Wildfire Games.
+/* Copyright (C) 2024 Wildfire Games.
  * This file is part of 0 A.D.
  *
  * 0 A.D. is free software: you can redistribute it and/or modify
@@ -75,6 +75,7 @@ enum NetMessageType
 
 	NMT_LOADED_GAME,
 	NMT_GAME_START,
+	NMT_SAVED_GAME_START,
 	NMT_END_COMMAND_BATCH,
 
 	NMT_SYNC_CHECK,	// OOS-detection hash checking
@@ -88,6 +89,7 @@ enum NetMessageType
 enum AuthenticateResultCode
 {
 	ARC_OK,
+	ARC_OK_SAVED_GAME,
 	ARC_OK_REJOINING,
 	ARC_PASSWORD_INVALID,
 };
@@ -226,6 +228,10 @@ START_NMT_CLASS_(GameStart, NMT_GAME_START)
 	NMT_FIELD(CStr, m_InitAttributes)
 END_NMT_CLASS()
 
+START_NMT_CLASS_(GameSavedStart, NMT_SAVED_GAME_START)
+	NMT_FIELD(CStr, m_InitAttributes)
+END_NMT_CLASS()
+
 START_NMT_CLASS_(EndCommandBatch, NMT_END_COMMAND_BATCH)
 	NMT_FIELD_INT(m_Turn, u32, 4)
 	NMT_FIELD_INT(m_TurnLength, u32, 2)