net: move BanMan to its own files

src/test/denialofservice_tests.cpp

@@ -4,6 +4,7 @@
 
 // Unit tests for denial-of-service detection/prevention code
 
+#include <banman.h>
 #include <chainparams.h>
 #include <keystore.h>
 #include <net.h>

src/test/test_bitcoin.cpp

@@ -4,6 +4,7 @@
 
 #include <test/test_bitcoin.h>
 
+#include <banman.h>
 #include <chainparams.h>
 #include <consensus/consensus.h>
 #include <consensus/params.h>

src/test/test_bitcoin_main.cpp

@@ -4,6 +4,7 @@
 
 #define BOOST_TEST_MODULE Bitcoin Test Suite
 
+#include <banman.h>
 #include <net.h>
 
 #include <memory>