Added event_chars property to confirm_done event (#782)

* Added event_chars property to confirm_done event

Currently it seems there is no way for someone listening to the
`confirm_done` event to know exactly what character was used to commit
the completion confirmation.

This commit adds a `event_chars` property to the `confirm_done` event.
Its value is just the `chars` variable form the `core.on_keymap`
function.

* Renamed `commid_chars` to `commit_character`

lua/cmp/core.lua

@@ -119,6 +119,7 @@ core.on_keymap = function(self, keys, fallback)
     local is_printable = char.is_printable(string.byte(chars, 1))
     self:confirm(e, {
       behavior = is_printable and 'insert' or 'replace',
+      commit_character = chars,
     }, function()
       local ctx = self:get_context()
       local word = e:get_word()
@@ -429,6 +430,7 @@ core.confirm = function(self, e, option, callback)
       release()
       self.event:emit('confirm_done', {
         entry = e,
+        commit_character = option.commit_character,
       })
       if callback then
         callback()

lua/cmp/types/cmp.lua

@@ -38,6 +38,7 @@ cmp.ItemField.Menu = 'menu'
 
 ---@class cmp.ConfirmOption
 ---@field public behavior cmp.ConfirmBehavior
+---@field public commit_character? string
 
 ---@class cmp.SelectOption
 ---@field public behavior cmp.SelectBehavior