Log Message:
fzf: update to 0.27.3.

0.27.3
------
- Preview window is `hidden` by default when there are `preview` bindings but
  `--preview` command is not given
- Fixed bug where `{n}` is not properly reset on `reload`
- Fixed bug where spinner is not displayed on `reload`
- Enhancements in tcell renderer for Windows (#2616)
- Vim plugin
    - `sinklist` is added as a synonym to `sink*` so that it's easier to add
      a function to a spec dictionary
      ```vim
      let spec = { 'source': 'ls', 'options': ['--multi', '--preview', 'cat {}'] }
      function spec.sinklist(matches)
        echom string(a:matches)
      endfunction

      call fzf#run(fzf#wrap(spec))
      ```
    - Vim 7 compatibility