Report processing improvements (#2349)

* Expose media attachments on reported statuses directly

* Comment out unused bulk report checkbox. Add title to report comment for viewing full comment. Add 'contents' column, with icons and numerical indicators to show the number of referenced statuses and media attachments in the report

* Link account name on authorize_follow card back to account

* Add localisation string for report_contents

* Show new admin accounts card partial on report view. Apply simple_format to report comment so newlines are preserved.

* Add new admin accounts card partial, for display quick useful admin stats (e.g. report history, moderation status).

* Fix localized variable