core, core/state, core/vm: remove exported account getters (#3618)

Removed exported statedb object accessors, reducing the chance for nasty
bugs to creep in. It's also ugly and unnecessary to have these methods.

core/vm/logger.go

@@ -144,7 +144,8 @@ func (l *StructLogger) CaptureState(env *EVM, pc uint64, op OpCode, gas, cost *b
 			storage = make(Storage)
 			// Get the contract account and loop over each storage entry. This may involve looping over
 			// the trie and is a very expensive process.
-			env.StateDB.GetAccount(contract.Address()).ForEachStorage(func(key, value common.Hash) bool {
+
+			env.StateDB.ForEachStorage(contract.Address(), func(key, value common.Hash) bool {
 				storage[key] = value
 				// Return true, indicating we'd like to continue.
 				return true