p2p: Integrate DumpAnchors() and ReadAnchors() into CConnman

src/net.h

@@ -566,6 +566,12 @@ private:
     /** Pointer to this node's banman. May be nullptr - check existence before dereferencing. */
     BanMan* m_banman;
 
+    /**
+     * Addresses that were saved during the previous clean shutdown. We'll
+     * attempt to make block-relay-only connections to them.
+     */
+    std::vector<CAddress> m_anchors;
+
     /** SipHasher seeds for deterministic randomness */
     const uint64_t nSeed0, nSeed1;