Reorganize the project folders

[yahoNanJing]

Is your feature request related to a problem or challenge? Please describe what you are trying to do.

Currently the datafusion related modules are organized directly under the project. It's better to downgrade them and organize them under one directory. And after #2076, the data access layer no longer depends on the datafusion, it's better to make it directly under the project.

Describe the solution you'd like

Then the whole project folders will be organized like follows:

Describe alternatives you've considered

Additional context

It's blocked by #2076.