Format file path in references preview.

[shatoba97]

Hi, your plugin is wonderful, thank you for your work.
I can't find a solution to format the file path in the preview of finding references.

It works good for the telescope find files, and I guess something rewrite my config
My config func for Telescope:

[fannheyward]

telescope-coc.nvim didn't use the lsp_references picker, instead pickers.new one. PR is welcome for this.