refactor: 重构trustlog-sdk目录结构到trustlog/go-trustlog

- 将所有trustlog-sdk文件移动到trustlog/go-trustlog/目录
- 更新README中所有import路径从trustlog-sdk改为go-trustlog
- 更新cookiecutter配置文件中的项目名称
- 更新根目录.lefthook.yml以引用新位置的配置
- 添加go.sum文件到版本控制
- 删除过时的示例文件

这次重构与trustlog-server保持一致的目录结构，
为未来支持多语言SDK（Python、Java等）预留空间。

api/grpc/common.proto

@@ -0,0 +1,20 @@
+syntax = "proto3";
+
+package common;
+
+option go_package = "go.yandata.net/iod/iod/trustlog-sdk/api/grpc/pb;pb";
+
+message MerkleTreeProofItem {
+	uint32 floor = 1;
+	string hash = 2;
+	bool  left = 3;
+}
+
+message Proof {
+	repeated MerkleTreeProofItem colItems = 1;
+	repeated MerkleTreeProofItem rawItems = 2;
+	repeated MerkleTreeProofItem colRootItem = 3;
+	repeated MerkleTreeProofItem rawRootItem = 4;
+	string sign = 5;
+	string version = 6; // 版本号
+}