Maybe provide ContractReferenceState in options

[todo]

contract-plugin/src/contract_csharp_generator.cc

Lines 366 to 371 in 7e905a5

	// TODO: Maybe provide ContractReferenceState in options
	out->Print("public class $classname$ : global::AElf.Sdk.CSharp.State.ContractReferenceState\n",
	"classname", GetReferenceClassName(service));
	out->Print("{\n");
	{
	out->Indent();

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This issue was generated by todo based on a TODO comment in 7e905a5. It's been assigned to @gldeng because they committed the code.