feat: move fee payer into fee struct

Author: ratik

proto/feerefunder/fee.proto

@@ -28,6 +28,7 @@ message Fee {
     (gogoproto.nullable) = false,
     (gogoproto.castrepeated) = "github.com/cosmos/cosmos-sdk/types.Coins"
   ];
+  string payer = 4;
 }
 
 message PacketID {

proto/interchaintxs/v1/tx.proto

@@ -51,13 +51,11 @@ message MsgSubmitTx {
 
   neutron.feerefunder.Fee fee = 7
       [ (gogoproto.nullable) = false ];
-
-  string fee_payer = 8;
 }
 
 // MsgSubmitTxResponse defines the response for Msg/SubmitTx
 message MsgSubmitTxResponse {
-  // channel's sequence_id for outgoing ibc packet. Unique per a channel.
+  // channel's sequence_id for outgoing ibc packet. Unique per a channel.y
   uint64 sequence_id = 1;
   // channel src channel on neutron side trasaction was submitted from
   string channel = 2;

proto/transfer/v1/tx.proto

@@ -43,7 +43,6 @@ message MsgTransfer {
 
   neutron.feerefunder.Fee fee = 8
       [ (gogoproto.nullable) = false ];
-  string fee_payer = 9;
 }
 
 // MsgTransferResponse is the modified response type for

x/feerefunder/types/fee.pb.go

@@ -83,10 +83,10 @@ func (k Keeper) SubmitTx(goCtx context.Context, msg *ictxtypes.MsgSubmitTx) (*ic
 		return nil, sdkerrors.Wrapf(ictxtypes.ErrNotContract, "%s is not a contract address", msg.FromAddress)
 	}
 
-	feePayerAddr, err := sdk.AccAddressFromBech32(msg.FeePayer)
-	if msg.FeePayer != "" && err != nil {
-		k.Logger(ctx).Debug("SubmitTx: failed to parse fee payer address", "fee_payer", msg.FeePayer)
-		return nil, sdkerrors.Wrapf(sdkerrors.ErrInvalidAddress, "failed to parse address: %s", msg.FeePayer)
+	feePayerAddr, err := sdk.AccAddressFromBech32(msg.Fee.Payer)
+	if msg.Fee.Payer != "" && err != nil {
+		k.Logger(ctx).Debug("SubmitTx: failed to parse fee payer address", "fee payer", msg.Fee.Payer)
+		return nil, sdkerrors.Wrapf(sdkerrors.ErrInvalidAddress, "failed to parse address: %s", msg.Fee.Payer)
 	}
 
 	params := k.GetParams(ctx)