refs https://github.com/TryGhost/Team/issues/1001
Our email newsletter preview is rendered inside of an iframe with
javascript disabled. When opening links from the preview, the new
window/tab inherits this property - which breaks links to twitter.
closes https://github.com/TryGhost/Ghost/issues/13684
refs 7eda410dc3
- ensures any `<DOCTYPE html>` (or equivalent) served when fetching preview html is passed through when replacing iframe contents
- replicates across all previews the fix for missing attributes on the `<html>` element that was put in for the design settings preview - using `documentElement.outerHTML` in place of `documentElement.innerHTML`
refs https://github.com/TryGhost/Team/issues/559
- moved the modal component class, template, and sub-components into a `components/modals/` directory to keep the top-level dir cleaner
- migrated component class to full glimmer syntax
