1786 git next prev land on dirs (#1787)

* 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>

lua/nvim-tree/explorer/common.lua

@@ -10,9 +10,7 @@ local function get_dir_git_status(parent_ignored, status, absolute_path)
     return file_status
   end
 
-  if M.config.git.show_on_dirs then
-    return status.dirs and status.dirs[absolute_path]
-  end
+  return status.dirs and status.dirs[absolute_path]
 end
 
 local function get_git_status(parent_ignored, status, absolute_path)
@@ -41,6 +39,22 @@ function M.update_git_status(node, parent_ignored, status)
   end
 end
 
+function M.shows_git_status(node)
+  if not node.git_status then
+    -- status doesn't exist
+    return false
+  elseif not node.nodes then
+    -- status exist and is a file
+    return true
+  elseif not node.open then
+    -- status exist, is a closed dir
+    return M.config.git.show_on_dirs
+  else
+    -- status exist, is a open dir
+    return M.config.git.show_on_dirs and M.config.git.show_on_open_dirs
+  end
+end
+
 function M.node_destroy(node)
   if not node then
     return