evm: move ChainConfig to Params (#266)

* evm: move ChainConfig to Params

* fixes

* fix test

ethereum/rpc/backend/backend.go

@@ -17,7 +17,6 @@ import (
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/common/hexutil"
 	ethtypes "github.com/ethereum/go-ethereum/core/types"
-	"github.com/ethereum/go-ethereum/params"
 
 	ethermint "github.com/tharsis/ethermint/types"
 	evmtypes "github.com/tharsis/ethermint/x/evm/types"
@@ -42,8 +41,6 @@ type Backend interface {
 	// Used by log filter
 	GetTransactionLogs(txHash common.Hash) ([]*ethtypes.Log, error)
 	BloomStatus() (uint64, uint64)
-
-	ChainConfig() *params.ChainConfig
 }
 
 var _ Backend = (*EVMBackend)(nil)
@@ -383,14 +380,3 @@ func (e *EVMBackend) GetLogsByNumber(blockNum types.BlockNumber) ([][]*ethtypes.
 func (e *EVMBackend) BloomStatus() (uint64, uint64) {
 	return 4096, 0
 }
-
-// ChainConfig returns the chain configuration for the chain. This method returns a nil pointer if
-// the query fails.
-func (e *EVMBackend) ChainConfig() *params.ChainConfig {
-	res, err := e.queryClient.QueryClient.ChainConfig(e.ctx, &evmtypes.QueryChainConfigRequest{})
-	if err != nil {
-		return nil
-	}
-
-	return res.Config.EthereumConfig(e.chainID)
-}