[Feature Request]: Refactor catalog commit.

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

- [X] I have checked the existing issues.

### Is your feature request related to a problem?

_No response_

### Describe the feature you'd like

1. add block entry and segment entry in txn_store.
2. Remove delta op out from constructor.
3. Refactor: txn commit
4. Refactor: delta log merge.

### Describe implementation you've considered

_No response_

### Documentation, adoption, use case

_No response_

### Additional information

_No response_

No files, tests, or entry points are named. Start by locating txn_store and the transaction commit and delta-log merge implementations, then trace how block and segment entries and delta operations are currently handled. Done means the four listed refactors are implemented and covered by the repository's relevant tests.

Written by the indexing model from the issue text.