* Filtered dir with git status that are open when show_on_open_dir is false
* refactored for single source of truth of existence of git status on a node
Putting `has_git_status()` in `explorer.common` because that's where node.status is constructed
Or at least I think that's where it's constructed
* 1786 semantic nit
Co-authored-by: Alexander Courtis <alex@courtis.org>