* block move operation that could introduce more than 8 level of depth, forbid circular reference
* move getHeight to store, mock store in service
* fix linter
* transfer DeleteFolder changes from larger PR
* finish some thingies
* add the simplest delete logics
* some intermedia steps
* fix tests
* add test
* fix some comments
Co-authored-by: yangkb09 <yangkb09@gmail.com>
* Folder: Add folder service implementation
* Add Move
* Add tests
* Add new servie method and adjust Update, Delete and Move
* Remove contains
* GetTree return children of depth one