feat(nut): make tab.tablist customizable and modular

[MunifTanjim]

local nut = {
  tab = {
    tablist = {
      create = require("nougat.nut.tab.tablist").create,
      close = require("nougat.nut.tab.tablist.close"),
      icon = require("nougat.nut.tab.tablist.icon"),
      label = require("nougat.nut.tab.tablist.label"),
      modified = require("nougat.nut.tab.tablist.modified"),
    },
  },
}

local tal = Bar("tabline")

tal:add_item(nut.tab.tablist.create({
  active_tab = {
    hl = { bg = "purple", fg = "white" },
    sep_left = sep.left_lower_triangle_solid(),
    suffix = " ",
    sep_right = sep.right_lower_triangle_solid(),
    content = {
      nut.tab.tablist.icon.create({
        suffix = " ",
      }),
      nut.tab.tablist.label.create({}),
      nut.tab.tablist.modified.create({
        prefix = " ",
      }),
      nut.tab.tablist.close.create({
        prefix = " ",
      }),
    },
  },
  inactive_tab = {
    hl = { bg = "gray35", fg = "gray65" },
    sep_left = sep.left_lower_triangle_solid(),
    suffix = " ",
    sep_right = sep.right_lower_triangle_solid(),
    content = {
      nut.tab.tablist.icon.create({
        suffix = " ",
      }),
      nut.tab.tablist.label.create({}),
      nut.tab.tablist.modified.create({
        prefix = " ",
      }),
      nut.tab.tablist.close.create({
        prefix = " ",
      }),
    },
  },
}))