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>

test/sanitizer_suppressions/tsan

@@ -13,7 +13,7 @@ race:zmq::*
 race:bitcoin-qt
 
 # deadlock (TODO fix)
-deadlock:CChainState::ConnectTip
+deadlock:Chainstate::ConnectTip
 
 # Intentional deadlock in tests
 deadlock:sync_tests::potential_deadlock_detected