refactor(#2826): remove view debug/cc, enable new codepaths for get_winid and get_bufnr (#3169)

* refactor(#2826): fuller error messages

* refactor(#2826): winnr->winid in view/globals, remove redundant get_winid and get_bufnr calls

* refactor(#2826): winnr->winid consistently

* refactor(#2826): consistent use of buffer registry, tidy, add todos

* refactor(#2826): remove unnecessary view members float, hide_root_folder; use explorer opts

* refactor(#2826): remove unused view members centralize_selection and preserve_window_proportions

* refactor(#2826): remove unused view member height

* refactor(#2826): temporarily reuse BUFNR_PER_TAB in view constructor

* refactor(#2826): get_winid returns new after consistency check

* refactor(#2826): globals.TABPAGES -> WINID_PER_TAB

* refactor(#2826): consistent naming of tabid

* refactor(#2826): more consistency checking

* refactor(#2826): more consistency checking

* refactor(#2826): move global CURSORS to view member

* Revert "refactor(#2826): move global CURSORS to view member"

This reverts commit d84dfad1c3.

* refactor(#2826): move global CURSORS to view member

* refactor(#2826): consistency check returns new

* refactor(#2826): remove consistency checks, enabling new path for view get_winid and get_bufnr

* refactor(#2826): restore CURSORS global

doc/nvim-tree-lua.txt

@@ -639,7 +639,6 @@ Following is the default configuration. See |nvim-tree-opts| for details. >lua
         },
       },
       experimental = {
-        multi_instance = false,
       },
       log = {
         enable = false,