feat(event): add WillCreateFile, WillRemoveFile (#2273)

node. These are mostly going to be useful for implementing lsp file
operation actions.

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

lua/nvim-tree/actions/fs/create-file.lua

@@ -9,6 +9,7 @@ local find_file = require("nvim-tree.actions.finders.find-file").fn
 local M = {}
 
 local function create_and_notify(file)
+  events._dispatch_will_create_file(file)
   local ok, fd = pcall(vim.loop.fs_open, file, "w", 420)
   if not ok then
     notify.error("Couldn't create file " .. file)