[Tech Request]: sync checkpoint event in the logtail protocol and optimize partition state gc logic

### Is there an existing issue for the same tech request?

- [X] I have checked the existing issues.

### Does this tech request not affect user experience?

- [X] This tech request doesn't affect user experience.

### What would you like to be added ?

```Markdown
sync checkpoint event in the logtail protocol
1. the checkpoint timestamp can be used as the partition state GC timestamp
2. the partition state can be GC if there is new checkpoint and no active txns before the timestamp
```

### Why is this needed ?

_No response_

### Additional information

_No response_