[FEATURE] Lexer: Return call/mixin args string[] instead of string

[Shinigami92]

Pug Lexer Version: ~4.1.0 - package.json#L31

Node Version: v13

Input Pug

// https://pugjs.org/language/mixins.html#rest-arguments
mixin list(id, ...items)
  ul(id=id)
    each item in items
      li= item

+list('my-list', 1, 2, 3, 4)

The lexer returns a call or mixin token with args
args can be null or string
In the above example: "'my-list', 1, 2, 3, 4"

Now I tried to split this by , (prettier/plugin-pug#66 (comment))
But the problem is, that it also can contain json that has by itself commas
And that breaks my formatter :(
So I need a string[] instead

['my-list', 1, 2, 3, 4]