Problem: fixed order of items in insert-mode completion menu
Solution: Introduce the 'completeitemalign' option with default
value "abbr,kind,menu" (glepnir).
Adding an new option `completeitemalign` abbr is `cia` to custom
the complete-item order in popupmenu.
closes: vim/vim#14006closes: vim/vim#157606a89c94a9e