feat: storage redesign

[skyzh]

In this PR, we redesigned the storage part to:

• Firstly, support single insert.
• Then, support multiple inserts, while introducing the terminology of RowSet.
• The rest as before, We will go with memtable, block, column, sparse index, etc.

Also, we changed the way to develop the tutorial.

Now everything will be tracked on storage branch. We will use a bash script to generate 03-xx from the git history.

This PR should not be merged. It only serves as a PR for tracking progress.