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)

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

@@ -81,6 +81,7 @@ function M.remove(node)
     end
     events._dispatch_folder_removed(node.absolute_path)
   else
+    events._dispatch_will_remove_file(node.absolute_path)
     local success = vim.loop.fs_unlink(node.absolute_path)
     if not success then
       return notify.error("Could not remove " .. node.name)

lua/nvim-tree/actions/fs/trash.lua

@@ -75,6 +75,7 @@ function M.fn(node)
         end
       end)
     else
+      events._dispatch_will_remove_file(node.absolute_path)
       trash_path(function(_, rc)
         if rc ~= 0 then
           notify.warn("trash failed: " .. err_msg .. "; please see :help nvim-tree.trash")