Add first-available-block command

client/src/rpc_request.rs

@@ -21,6 +21,7 @@ pub enum RpcRequest {
     GetFeeCalculatorForBlockhash,
     GetFeeRateGovernor,
     GetFees,
+    GetFirstAvailableBlock,
     GetGenesisHash,
     GetIdentity,
     GetInflationGovernor,
@@ -74,6 +75,7 @@ impl fmt::Display for RpcRequest {
             RpcRequest::GetFeeCalculatorForBlockhash => "getFeeCalculatorForBlockhash",
             RpcRequest::GetFeeRateGovernor => "getFeeRateGovernor",
             RpcRequest::GetFees => "getFees",
+            RpcRequest::GetFirstAvailableBlock => "getFirstAvailableBlock",
             RpcRequest::GetGenesisHash => "getGenesisHash",
             RpcRequest::GetIdentity => "getIdentity",
             RpcRequest::GetInflationGovernor => "getInflationGovernor",