Includes: Cleanup around net main and wallet

-Move from .h to .cpp: in main, net and wallet
-Remove unnecessary #include "main.h"
-Cleanup some wallet files includes

src/qt/rpcconsole.cpp

@@ -10,7 +10,6 @@
 #include "peertablemodel.h"
 #include "scicon.h"
 
-#include "main.h"
 #include "chainparams.h"
 #include "rpcserver.h"
 #include "rpcclient.h"