Merge bitcoin#28224: shutdown: Destroy kernel last, make test shutdown order consistent

c1144f0 tests: Reset node context members on ~BasicTestingSetup (TheCharlatan)
9759af1 shutdown: Destroy kernel last (TheCharlatan)

Pull request description:

  The destruction/resetting of node context members in the tests should roughly follow the behavior of the `Shutdown` function in `init.cpp`.

  This was originally requested by MarcoFalke in this [comment](bitcoin#25065 (comment)) in response to the [original pull request](bitcoin#25065) introducing the `kernel::Context`.

ACKs for top commit:
  maflcko:
    ACK c1144f0 🗣
  achow101:
    ACK c1144f0
  ryanofsky:
    Code review ACK c1144f0. No code changes since last review, just updated commits and descriptions

Tree-SHA512: 819bb85ff82a5c6c60e429674d5684f3692fe9062500d00a87b361cc59e6bda145be21b5a4466dee6791faed910cbde4d26baab325bf6daa1813af13a63588ff

Author: achow101

src/init.cpp

@@ -343,11 +343,11 @@ void Shutdown(NodeContext& node)
     node.chain_clients.clear();
     UnregisterAllValidationInterfaces();
     GetMainSignals().UnregisterBackgroundSignalScheduler();
-    node.kernel.reset();
     node.mempool.reset();
     node.fee_estimator.reset();
     node.chainman.reset();
     node.scheduler.reset();
+    node.kernel.reset();
 
     try {
         if (!fs::remove(GetPidFile(*node.args))) {

src/test/util/setup_common.cpp

@@ -147,6 +147,7 @@ BasicTestingSetup::BasicTestingSetup(const ChainType chainType, const std::vecto
 
 BasicTestingSetup::~BasicTestingSetup()
 {
+    m_node.kernel.reset();
     SetMockTime(0s); // Reset mocktime for following tests
     LogInstance().DisconnectTestLogger();
     fs::remove_all(m_path_root);
@@ -205,8 +206,9 @@ ChainTestingSetup::~ChainTestingSetup()
     m_node.netgroupman.reset();
     m_node.args = nullptr;
     m_node.mempool.reset();
-    m_node.scheduler.reset();
+    m_node.fee_estimator.reset();
     m_node.chainman.reset();
+    m_node.scheduler.reset();
 }
 
 void ChainTestingSetup::LoadVerifyActivateChainstate()