chore: cleanup deprecated BalanceChangeEntry (cosmos#506)

* chore: align balance change reason for tracing

for more info, https://github.com/ethereum/go-ethereum/blob/v1.16.2/core/evm.go#L143

* cleanup deprecated BalanceChangeEntry

for more info, https://github.com/cosmos/evm/pull/201/files

* Revert "chore: align balance change reason for tracing"

This reverts commit 07a628c.

Author: mmsqe

precompiles/common/precompile.go

@@ -7,7 +7,6 @@ import (
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/core/tracing"
 	"github.com/ethereum/go-ethereum/core/vm"
-	"github.com/holiman/uint256"
 
 	"github.com/cosmos/evm/x/vm/statedb"
 
@@ -35,16 +34,6 @@ const (
 	Add
 )
 
-type BalanceChangeEntry struct {
-	Account common.Address
-	Amount  *uint256.Int
-	Op      Operation
-}
-
-func NewBalanceChangeEntry(acc common.Address, amt *uint256.Int, op Operation) BalanceChangeEntry {
-	return BalanceChangeEntry{acc, amt, op}
-}
-
 // RequiredGas calculates the base minimum required gas for a transaction or a query.
 // It uses the method ID to determine if the input is a transaction or a query and
 // uses the Cosmos SDK gas config flat cost and the flat per byte cost * len(argBz) to calculate the gas.