chore: remove RPCs, Request types, add mock responses until removed f…

…rom dependency. (#6433)

* chore: remove RPCs, Request types, add mock responses until removed from dependency.

* lint: make lint-fix

* chore: fix proto issues

---------

Co-authored-by: chatton <cian@interchain.io>

modules/apps/transfer/keeper/grpc_query.go

@@ -159,15 +159,3 @@ func (k Keeper) TotalEscrowForDenom(c context.Context, req *types.QueryTotalEscr
 		Amount: amount,
 	}, nil
 }
-
-// DenomTrace implements the Query/DenomTrace gRPC method
-// Deprecated: Please use Denom instead.
-func (Keeper) DenomTrace(c context.Context, req *types.QueryDenomTraceRequest) (*types.QueryDenomTraceResponse, error) {
-	return nil, status.Error(codes.Unimplemented, "unsupported rpc")
-}
-
-// DenomTraces implements the Query/DenomTraces gRPC method
-// Deprecated: Please use Denoms instead.
-func (Keeper) DenomTraces(c context.Context, req *types.QueryDenomTracesRequest) (*types.QueryDenomTracesResponse, error) {
-	return nil, status.Error(codes.Unimplemented, "unsupported rpc")
-}

modules/apps/transfer/types/legacy_denomtrace.go

@@ -0,0 +1,8 @@
+package types
+
+// TODO: https://github.com/cosmos/ibc-go/issues/6421#issuecomment-2137516426
+// Kept around due to dependency. Empty and useless and ideally dropped before v9.
+type (
+	QueryDenomTracesResponse struct{}
+	QueryDenomTraceResponse  struct{}
+)