[CSM] Add flavour limits controlled by server (#5930)

* [CSM] Add flavour limits controlled by server

Server send flavour limits to client permitting to disable or limit some Lua calls

* Add limits for reading nodedefs and itemdefs

* flavour: Add lookup node limits

* Merge get_node_or_nil into get_node.

Sending fake node doesn't make sense in CSM, just return nil if node is not available for any reason

* Add node range customization when noderange flavour is enabled (default 8 nodes)

* Limit nodes range & disable chat message sending by default

* Bump protocol version

src/network/clientpackethandler.cpp

@@ -1376,3 +1376,8 @@ void Client::handleCommand_SrpBytesSandB(NetworkPacket* pkt)
 	resp_pkt << std::string(bytes_M, len_M);
 	Send(&resp_pkt);
 }
+
+void Client::handleCommand_CSMFlavourLimits(NetworkPacket *pkt)
+{
+	*pkt >> m_csm_flavour_limits >> m_csm_noderange_limit;
+}