[GD-55] Add gas estimation function (#2)

* Add gas estimation function

* Fix example

Author: sidorovkirill

Assets/AnkrSDK/Examples/UseCases/UpdateNFT/UpdateNftExample.cs

@@ -60,6 +60,13 @@ public async void UpdateNFT()
 			Debug.Log($"Receipt: {receipt}");
 		}
 
+		public async void EstimateGas()
+		{
+			var info = await RequestPreparedParams(0);
+			var gasEstimation = await _contract.EstimateGas("updateTokenWithSignedMessage", new object[] {info});
+			Debug.Log("Gas estimation = "+gasEstimation);
+		}
+
 		private async Task<ItemInfo> RequestPreparedParams(int tokenId)
 		{
 			var request = UnityWebRequest.Get(URL + $"hero/{tokenId}");

Assets/AnkrSDK/Scripts/Core/Implementation/Contract.cs

@@ -8,6 +8,7 @@
 using Cysharp.Threading.Tasks;
 using Nethereum.ABI.FunctionEncoding.Attributes;
 using Nethereum.Contracts;
+using Nethereum.Hex.HexTypes;
 using Nethereum.RPC.Eth.DTOs;
 using Nethereum.Web3;
 
@@ -108,5 +109,18 @@ private TransactionInput CreateTransactionInput(string methodName, object[] argu
 			var callFunction = contract.GetFunction(methodName);
 			return callFunction.CreateTransactionInput(activeSessionAccount, arguments);
 		}
+		
+		
+		public Task<HexBigInteger> EstimateGas(string methodName, object[] arguments = null, string gas = null,
+			string gasPrice = null, string nonce = null)
+		{
+			var transactionInput = CreateTransactionInput(methodName, arguments);
+
+			transactionInput.Gas = gas != null ? new HexBigInteger(gas) : null;
+			transactionInput.GasPrice = gasPrice != null ? new HexBigInteger(gasPrice) : null;
+			transactionInput.Nonce = nonce != null ? new HexBigInteger(nonce) : null;
+			
+			return _web3Provider.TransactionManager.EstimateGasAsync(transactionInput);
+		}
 	}
 }

Assets/AnkrSDK/Scripts/Core/Infrastructure/IContract.cs

@@ -4,6 +4,7 @@
 using AnkrSDK.Core.Events;
 using Nethereum.ABI.FunctionEncoding.Attributes;
 using Nethereum.Contracts;
+using Nethereum.Hex.HexTypes;
 
 namespace AnkrSDK.Core.Infrastructure
 {
@@ -20,5 +21,8 @@ Task<List<EventLog<TEvDto>>> GetAllChanges<TEvDto>(EventFilterData evFilter = nu
 
 		Task<TReturnType> GetData<TFieldData, TReturnType>(TFieldData requestData = null)
 			where TFieldData : FunctionMessage, new();
+
+		Task<HexBigInteger> EstimateGas(string methodName, object[] arguments = null, string gas = null,
+			string gasPrice = null, string nonce = null);
 	}
 }