scripted-diff: rename CChainState -> Chainstate

-BEGIN VERIFY SCRIPT-
sed -i 's/CChainState/Chainstate/g' $(git grep -l CChainState ':(exclude)doc/release-notes*')
-END VERIFY SCRIPT-

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

src/node/blockstorage.cpp

@@ -882,7 +882,7 @@ void ThreadImport(ChainstateManager& chainman, std::vector<fs::path> vImportFile
         // We can't hold cs_main during ActivateBestChain even though we're accessing
         // the chainman unique_ptrs since ABC requires us not to be holding cs_main, so retrieve
         // the relevant pointers before the ABC call.
-        for (CChainState* chainstate : WITH_LOCK(::cs_main, return chainman.GetAll())) {
+        for (Chainstate* chainstate : WITH_LOCK(::cs_main, return chainman.GetAll())) {
             BlockValidationState state;
             if (!chainstate->ActivateBestChain(state, nullptr)) {
                 LogPrintf("Failed to connect best block (%s)\n", state.ToString());