add rpc `eth_estimateGas` - dependency for blob spammer (#2701)

* add eth_estimateGas, dependency for blob spammer

* remove restriction

* fix indentation

kurtosis-network-params.yml

@@ -20,8 +20,6 @@ additional_services:
   - tx_spammer
   - assertoor
   - beacon_metrics_gazer
-tx_spammer_params:
-  tx_spammer_extra_args: ["--accounts=1", "--txcount=1"]
 mev_type: null
 assertoor_params:
   image: "ethpandaops/assertoor:master"

nimbus/rpc/server_api.nim

@@ -304,3 +304,18 @@ proc setupServerAPI*(api: ServerAPIRef, server: RpcServer) =
           return populateReceipt(receipt, gasUsed, blkdesc.blk.transactions[txid], txid, blkdesc.blk.header)
 
         idx.inc
+  
+  server.rpc("eth_estimateGas") do(args: TransactionArgs) -> Web3Quantity:
+    ## Generates and returns an estimate of how much gas is necessary to allow the transaction to complete.
+    ## The transaction will not be added to the blockchain. Note that the estimate may be significantly more than
+    ## the amount of gas actually used by the transaction, for a variety of reasons including EVM mechanics and node performance.
+    ##
+    ## args: the transaction call object.
+    ## quantityTag:  integer block number, or the string "latest", "earliest" or "pending", see the default block parameter.
+    ## Returns the amount of gas used.
+    let
+      header   = api.headerFromTag(blockId("latest")).valueOr:
+        raise newException(ValueError, "Block not found")
+      gasUsed  = rpcEstimateGas(args, header, api.chain.com, DEFAULT_RPC_GAS_CAP).valueOr:
+        raise newException(ValueError, "rpcEstimateGas error: " & $error.code)
+    w3Qty(gasUsed)