### What problem were solved in this pull request?

Issue Number: close #162 

Problem:
当前的observer启动流程和调试方法比较繁琐，必须使用客户端服务端的方式，先启动服务端程序，再使用客户端启动调试

### What is changed and how it works?
observer可以直接启动，不监听tcp或unix socket，直接通过终端/控制台输入命令并执行，极大的方便了调试

### Other information
新的启动方法：
./bin/observer -P cli -f ../etc/observer.ini

### What problem were solved in this pull request?

close issue: #186 

Problem:
实现MVCC代码后没有将持久化代码合并进来

### What is changed and how it works?
支持并发模式下落日志，并在异常停机后回复。

持久化是事务模块中最复杂的功能（没有之一），当前miniob实现的持久化简化了非常多，因此不能依赖持久化能力，仅仅作为一个学习测试的工具，在实际测试时也有一些限制。

### Other information

fix unittest;
add unittest to github action

### What problem were solved in this pull request?

Issue Number: close #176 close #163 

Problem:
单元测试执行失败；
github action 没有单元测试检查

Fix problem:
1. the buffer pool and b tree is not thread safe;
2. github/workflow/build does not work

### What is changed and how it works?
1. thread-safe buffer pool
- I use a mutex in buffer pool and take a lock in buffer pool operations
such as allocate frame, dispose frame;
- The frame is locked while updating/reading the content of frame;
- Frame manager take a lock when allocate/free pages.

2. thread-safe b+tree
- Crabing protocol is used to support concurrent

3. github/workflow/build
- update the submodules;
- create a build script and run build.sh in build.yaml