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

This reverts commit 38aac09151.

lua/nvim-tree/node/file.lua

@@ -1,49 +0,0 @@
-local utils = require("nvim-tree.utils")
-
-local BaseNode = require("nvim-tree.node")
-
----@class (exact) FileNode: BaseNode
----@field extension string
-local FileNode = BaseNode:new()
-
----Static factory method
----@param explorer Explorer
----@param parent Node
----@param absolute_path string
----@param name string
----@param fs_stat uv.fs_stat.result?
----@return FileNode
-function FileNode:create(explorer, parent, absolute_path, name, fs_stat)
-  ---@type FileNode
-  local o = {
-    type = "file",
-    explorer = explorer,
-    absolute_path = absolute_path,
-    executable = utils.is_executable(absolute_path),
-    fs_stat = fs_stat,
-    git_status = nil,
-    hidden = false,
-    is_dot = false,
-    name = name,
-    parent = parent,
-    watcher = nil,
-    diag_status = nil,
-
-    extension = string.match(name, ".?[^.]+%.(.*)") or "",
-  }
-  o = self:new(o) --[[@as FileNode]]
-
-  return o
-end
-
----Create a sanitized partial copy of a node, populating children recursively.
----@return FileNode cloned
-function FileNode:clone()
-  local clone = BaseNode.clone(self) --[[@as FileNode]]
-
-  clone.extension = self.extension
-
-  return clone
-end
-
-return FileNode