refactor(#2827): multi instance nvim-tree.live-filter (#2849)

* feat(#2827): Multi Instance: Refactor: nvim-tree.live-filter

* refactor: all usages going through the explorer

* fix: api and filtration

* fix: style

* Update lua/nvim-tree/api.lua

Co-authored-by: Alexander Courtis <alex@courtis.org>

* docs: add missing live filter luadocs

---------

Co-authored-by: Alexander Courtis <alex@courtis.org>

lua/nvim-tree/utils.lua

@@ -112,7 +112,10 @@ function M.find_node(nodes, fn)
     end)
     :iterate()
   i = require("nvim-tree.view").is_root_folder_visible() and i or i - 1
-  i = require("nvim-tree.live-filter").filter and i + 1 or i
+  local explorer = require("nvim-tree.core").get_explorer()
+  if explorer and explorer.live_filter.filter then
+    i = i + 1
+  end
   return node, i
 end