cli formatter can not get the source file name

[ttys3]

this PR #2942 added cli formatter support, this is great.

but in some formatters need the file path to location a config in the project (stylua) or use it to determine the file type (prettier),

in neovim we can use vim.api.nvim_buf_get_name(0) to get the current buf file path, but in hexlix seems no way to do so.

for example:

style:

--stdin-filepath Specify the location of the file that is being passed into stdin. Ignored
if not taking in input from stdin. This option is only used to help
determine where to find the configuration file

require("formatter").setup {
	filetype = {
		javascript = {
			-- prettier
			function()
				return {
					exe = "prettier",
					args = { "--stdin-filepath", vim.api.nvim_buf_get_name(0), "--single-quote" },
					stdin = true,
				}
			end,
		},
		lua = {
			-- stylua
			function()
				return {
					exe = "stylua",
					args = { "--search-parent-directories", "--stdin-filepath", vim.api.nvim_buf_get_name(0), "-" },
					stdin = true,
				}
			end,
		},
	}
}

[ttys3]

close due to duplicated with #3596