Check if state is available before tracing transaction

Before calling TraceTransaction here:
https://github.com/NethermindEth/nethermind/blob/master/src/Nethermind/Nethermind.JsonRpc/Modules/DebugModule/DebugRpcModule.cs#L70

Add check for state availability similar to other RPC modules, e.g. EthRpcModule (BlockchainBridge):
https://github.com/NethermindEth/nethermind/blob/master/src/Nethermind/Nethermind.Facade/BlockchainBridge.cs#L410-L413