Merge #13417: [net] Tighten scope in net_processing

3339ba28e9 Make g_enable_bip61 a member variable of PeerLogicValidation (Jesse Cohen)
6690a28606 Restrict as much as possible in net_processing to translation unit (Jesse Cohen)
1d4df02b7e [move-only] Move things only referenced in net_processing out of header file (Jesse Cohen)
02bbc05310 Rescope g_enable_bip61 to net_processing (Jesse Cohen)

Pull request description:

  As part of a larger effort to decouple net_processing and validation a bit, these are a bunch of simple scope cleanups. I've moved things out of the header file that are only referenced in net_processing and added static (or anonymous namespace) modifiers to everything possible in net_processing.

  There are a handful of functions which could be static except that they are exposed for the sake of unit testing - these are explicitly commented. There has been some discussion of a compile time annotation, but no conclusion has been reached on that yet.

  This is somewhat related to other prs #12934 #13413 #13407 and will be followed by prs that reduce reliance on cs_main to synchronize data structures which are translation unit local to net_processing

Tree-SHA512: 46c9660ee4e06653feb42ba92189565b0aea17aac2375c20747c0d091054c63829cbf66d2daddf65682b58ce1d6922e23aefea051a7f2c8abbb6db253a609082

src/test/denialofservice_tests.cpp

@@ -24,6 +24,8 @@
 extern bool AddOrphanTx(const CTransactionRef& tx, NodeId peer);
 extern void EraseOrphansFor(NodeId peer);
 extern unsigned int LimitOrphanTxSize(unsigned int nMaxOrphans);
+extern void Misbehaving(NodeId nodeid, int howmuch, const std::string& message="");
+
 struct COrphanTx {
     CTransactionRef tx;
     NodeId fromPeer;