'Rename' action throws an error when the target file already exists

[voldikss]

Hi @weirongxu

Description

Suppose there are two files a.txt and b.txt in one directory and I want to rename a.txt to b.txt. After executing rename action the extension throws an error

[coc.nvim] Error: Target file or directory /home/voldikss/dotfiles/README.md already exists

Expected

• If the target file already exist
  • If the target file is the source file itself(e.g. rename a.txt to a.txt), do nothing
  • Otherwise show a prompt with an option such as override? and ...