Merge bitcoin/bitcoin#28091: fuzz: use ConnmanTestMsg in connman

ecfe507 fuzz: use `ConnmanTestMsg` in `connman` (brunoerg)

Pull request description:

  Fixes #27980

  Using `ConnmanTestMsg` we can add nodes and be
  more effective fuzzing functions like `DisconnectNode`,
  `FindNode`, `GetNodeStats` and other ones.

ACKs for top commit:
  MarcoFalke:
    review ACK ecfe507
  dergoegge:
    utACK ecfe507

Tree-SHA512: 97c363b422809f2e9755c082d1102237347abfab72c7baca417bd8975f8a595ddf3a085f8353dbdb9f17fb98fbfe830792bfc0b83451168458018faf6c239efa

Author: fanquake

src/test/fuzz/connman.cpp

@@ -32,7 +32,7 @@ FUZZ_TARGET(connman, .init = initialize_connman)
 {
     FuzzedDataProvider fuzzed_data_provider{buffer.data(), buffer.size()};
     SetMockTime(ConsumeTime(fuzzed_data_provider));
-    CConnman connman{fuzzed_data_provider.ConsumeIntegral<uint64_t>(),
+    ConnmanTestMsg connman{fuzzed_data_provider.ConsumeIntegral<uint64_t>(),
                      fuzzed_data_provider.ConsumeIntegral<uint64_t>(),
                      *g_setup->m_node.addrman,
                      *g_setup->m_node.netgroupman,
@@ -41,6 +41,12 @@ FUZZ_TARGET(connman, .init = initialize_connman)
     CNode random_node = ConsumeNode(fuzzed_data_provider);
     CSubNet random_subnet;
     std::string random_string;
+
+    LIMITED_WHILE(fuzzed_data_provider.ConsumeBool(), 100) {
+        CNode& p2p_node{*ConsumeNodeAsUniquePtr(fuzzed_data_provider).release()};
+        connman.AddTestNode(p2p_node);
+    }
+
     LIMITED_WHILE(fuzzed_data_provider.ConsumeBool(), 10000) {
         CallOneOf(
             fuzzed_data_provider,
@@ -128,4 +134,6 @@ FUZZ_TARGET(connman, .init = initialize_connman)
     (void)connman.GetTotalBytesSent();
     (void)connman.GetTryNewOutboundPeer();
     (void)connman.GetUseAddrmanOutgoing();
+
+    connman.ClearTestNodes();
 }