Add setting for server sent commands per frame limit

Use higher of this and existing commands per frame limit setting
for server-originating commands, e.g. GS

src/network/network_command.cpp

@@ -286,6 +286,10 @@ static void DistributeQueue(CommandQueue *queue, const NetworkClientSocket *owne
 	int to_go = UINT16_MAX;
 #else
 	int to_go = _settings_client.network.commands_per_frame;
+	if (owner == nullptr) {
+		/* This is the server, use the commands_per_frame_server setting if higher */
+		to_go = std::max<int>(to_go, _settings_client.network.commands_per_frame_server);
+	}
 #endif
 
 	std::unique_ptr<CommandPacket> cp;

src/settings_type.h

@@ -353,6 +353,7 @@ struct NetworkSettings {
 	uint16      sync_freq;                                ///< how often do we check whether we are still in-sync
 	uint8       frame_freq;                               ///< how often do we send commands to the clients
 	uint16      commands_per_frame;                       ///< how many commands may be sent each frame_freq frames?
+	uint16      commands_per_frame_server;                ///< how many commands may be sent each frame_freq frames? (server-originating commands)
 	uint16      max_commands_in_queue;                    ///< how many commands may there be in the incoming queue before dropping the connection?
 	uint16      bytes_per_frame;                          ///< how many bytes may, over a long period, be received per frame?
 	uint16      bytes_per_frame_burst;                    ///< how many bytes may, over a short period, be received?

src/table/settings/network_settings.ini

@@ -69,6 +69,15 @@ min      = 1
 max      = 65535
 cat      = SC_EXPERT
 
+[SDTC_VAR]
+var      = network.commands_per_frame_server
+type     = SLE_UINT16
+flags    = SF_NOT_IN_SAVE | SF_NO_NETWORK_SYNC | SF_NETWORK_ONLY
+def      = 16
+min      = 1
+max      = 65535
+cat      = SC_EXPERT
+
 [SDTC_VAR]
 var      = network.max_commands_in_queue
 type     = SLE_UINT16