Show file and dir icons directly inside the label

[simonmandlik]

This is an extension of default label component that shows file and directory icons as part of the label for the path provider, keeping all functionality:

local default_file_icon = "x"
local default_dir_icon = "y"

completion.menu.draw.components.label = {
    text = function(ctx)
        local res = ctx.label .. ctx.label_detail
        if ctx.kind == "Folder" then
            res = default_dir_icon .. " " .. res
        elseif ctx.kind == "File" then
            local fname = ctx.item.data.full_path
            local icon = require("nvim-web-devicons").get_icon(fname)
            res = (icon and icon or default_file_icon) .. " " .. res
        end
        return res
    end,
    highlight = function(ctx)
        local highlights = {}
        local offset = 0
        if ctx.kind == "Folder" then
            table.insert(highlights, { 0, 1, group = "Directory"})
            offset = 1 + #default_dir_icon
        elseif ctx.kind == "File" then
            local fname = ctx.item.data.full_path
            local _, group = require("nvim-web-devicons").get_icon(fname)
            group = group and group or "BlinkCmpIconDefault"
            table.insert(highlights, { 0, 1, group = group })
            offset = 1 + #default_file_icon
        end
        table.insert(highlights, {
            offset, offset + #ctx.label,
            group = ctx.deprecated and "BlinkCmpLabelDeprecated" or "BlinkCmpLabel",
        })
        if ctx.label_detail then
            table.insert(highlights, {
                offset + #ctx.label,
                offset + #ctx.label + #ctx.label_detail,
                group = "BlinkCmpLabelDetail",
            })
        end
        -- characters matched on the label by the fuzzy matcher
        for _, idx in ipairs(ctx.label_matched_indices) do
            table.insert(highlights, {
                offset + idx, offset + idx + 1,
                group = "BlinkCmpLabelMatch",
            })
        end
        return highlights
    end
},