refactor: remove unused PIBinaryStream operators for PIMQTT message types

The operator<< / operator>> templates for MessageConst / MessageMutable
added in 4d8b7430 have no users in the tree (libs, tests, utils, main).
Drop them along with the pibinarystream.h include they required; the
binary-stream fallback static_assert in pibinarystream.h already gives a
clear compile error if external code ever streams an MQTT message.

libs/main/mqtt_common/pimqtttypes.h

@@ -25,7 +25,6 @@
 #ifndef pimqtttypes_h
 #define pimqtttypes_h
 
-#include "pibinarystream.h"
 #include "pip_export.h"
 #include "pistringlist.h"
 
@@ -160,26 +159,6 @@ public:
 	//! \~russian Возвращает ID сообщения.
 	MessageMutable & setID(int id);
 };
-template<typename P>
-inline PIBinaryStream<P> & operator<<(PIBinaryStream<P> & s, const MessageConst & v) {
-	s << v.topic() << v.pathArguments() << v.payload() << v.properties() << static_cast<int>(v.qos()) << v.ID() << v.isDuplicate();
-	return s;
-}
-
-template<typename P>
-inline PIBinaryStream<P> & operator>>(PIBinaryStream<P> & s, MessageMutable & v) {
-	PIString topic;
-	PIMap<PIString, PIString> path_args;
-	PIByteArray payload;
-	PIMap<int, PIString> props;
-	int qos_val, msg_id;
-	bool is_dup;
-	s >> topic >> path_args >> payload >> props >> qos_val >> msg_id >> is_dup;
-	v.setTopic(topic).setPayload(payload).setQos(static_cast<QoS>(qos_val)).setID(msg_id).setDuplicate(is_dup);
-	v.pathArguments() = path_args;
-	v.properties()    = props;
-	return s;
-}
 
 }; // namespace PIMQTT