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。

.gitignore

@@ -0,0 +1,26 @@
+# Cache folders generated by IDE
+.vscode/**
+.idea/**
+
+# Mac only
+.DS_Store/**
+
+# Ignore directories containing binaries generated and other stuff
+tmp/**
+bin/.gitignore
+coverage/**
+
+# Directories require atleast one file to be tracked by git.
+!tmp/.gitkeep
+!bin/.gitkeep
+!coverage/.gitkeep
+
+# Ignore config files from project root, keeping sample config files
+/configs**
+!/configs.**.sample
+
+# Ignore all secret files — they'll be used for project sensitive data
+**.secrets
+**.session
+**.secret
+**.cookie