Revert "refactor(#2871, #2886): multi instance: node classes created (#2916)"

This reverts commit 38aac09151.

lua/nvim-tree/enum.lua

@@ -1,13 +1,5 @@
 local M = {}
 
----Must be synced with uv.fs_stat.result as it is compared with it
----@enum (key) NODE_TYPE
-M.NODE_TYPE = {
-  directory = 1,
-  file = 2,
-  link = 4,
-}
-
 ---Setup options for "highlight_*"
 ---@enum HL_POSITION
 M.HL_POSITION = {