test: add basic tests for ChainstateManager

Feedback incorporated from Russell Yanofsky.

Co-authored-by: MarcoFalke <falke.marco@gmail.com>

src/test/util/setup_common.cpp

@@ -111,6 +111,7 @@ TestingSetup::TestingSetup(const std::string& chainName) : BasicTestingSetup(cha
     GetMainSignals().RegisterBackgroundSignalScheduler(*g_rpc_node->scheduler);
 
     pblocktree.reset(new CBlockTreeDB(1 << 20, true));
+
     g_chainman.InitializeChainstate();
     ::ChainstateActive().InitCoinsDB(
         /* cache_size_bytes */ 1 << 23, /* in_memory */ true, /* should_wipe */ false);