Pass NodeContext, ConnMan, BanMan references more places

So g_connman and g_banman globals can be removed next commit.

src/rpc/mining.cpp

@@ -13,6 +13,7 @@
 #include <key_io.h>
 #include <miner.h>
 #include <net.h>
+#include <node/context.h>
 #include <policy/fees.h>
 #include <pow.h>
 #include <rpc/blockchain.h>