cwgo doc 使用proto2 生成代码报错，能否支持下

[pigfu]

Describe the bug

命令：cwgo doc -idl order.proto --module app --dao_dir biz/dal/mongo --model_dir biz/model -I .

结果：[ERROR]D:/gopath/pkg/mod/github.com/cloudwego/[email protected]/cwgo.go:47: can not find Id field in struct Order

实际Order结构体如下：

type Order struct {
	state         protoimpl.MessageState
	sizeCache     protoimpl.SizeCache
	unknownFields protoimpl.UnknownFields

	Id         *string `protobuf:"bytes,1,opt,name=id" json:"id,omitempty"` // go.tag=|bson:"id,omitempty"|
	UserId     *string `protobuf:"bytes,2,opt,name=user_id,json=userId" json:"user_id,omitempty"`
	Type       *string `protobuf:"bytes,3,opt,name=type" json:"type,omitempty"`
	Name       *string `protobuf:"bytes,4,opt,name=name" json:"name,omitempty"`
	Price      *string `protobuf:"bytes,5,opt,name=price" json:"price,omitempty"`
	CreateTime *string `protobuf:"bytes,6,opt,name=create_time,json=createTime" json:"create_time,omitempty"`
	UpdateTime *string `protobuf:"bytes,7,opt,name=update_time,json=updateTime" json:"update_time,omitempty"`
	Status     *string `protobuf:"bytes,8,opt,name=status" json:"status,omitempty"`
}

猜测是指针的原因