feat: format JS template embeds

CSS, GraphQL, Markdown and HTML in JS templates are formatted as
Prettier does by default, through tidy's own formatters. Their doc
streams become JS IR, so the template's real column and width apply.
46 of 50 embed fixtures match Prettier (19 before). The JS oracle
passed formatEmbedded, which the binding ignores; it passes embedded
now, and --embedded turns embedding on for both tools.