sy/mv-out-of-cone (was Re: What's cooking in git.git (Aug 2022, #05; Mon, 15))

> * sy/mv-out-of-cone (2022-08-10) 9 commits
>  - mv: check overwrite for in-to-out move
>  - advice.h: add advise_on_moving_dirty_path()
>  - mv: cleanup empty WORKING_DIRECTORY
>  - mv: from in-cone to out-of-cone
>  - mv: remove BOTH from enum update_mode
>  - mv: check if <destination> is a SKIP_WORKTREE_DIR
>  - mv: free the with_slash in check_dir_in_index()
>  - mv: rename check_dir_in_index() to empty_dir_has_sparse_contents()
>  - t7002: add tests for moving from in-cone to out-of-cone
> 
>  "git mv A B" in a sparsely populated working tree can be asked to
>  move a path from a directory that is "in cone" to another directory
>  that is "out of cone".  Handling of such a case has been improved.
> 
>  Will merge to 'next'?
>  source: <20220809120910.2021413-1-shaoxuan.yuan02@gmail.com>
>