Added read message max size in socket communication (#42)

* Added peermaxmsg size to config

* Completed inital implementation

* Completed adding message max size

* Refactored code

* Refactored code to have data types using std library

* Added peer maxmpm

* Added const to session_options

src/p2p/peer_session_handler.cpp

@@ -11,7 +11,7 @@
 
 namespace p2p
 {
-
+    
 peer_outbound_message::peer_outbound_message(
     std::shared_ptr<flatbuffers::FlatBufferBuilder> _fbbuilder_ptr)
 {