Show the length of videos and animated posts in the thumbnail. The
length is shown the top left corner in MM:SS format. This replaces the
play button icon.
Show a speaker icon instead of a music note icon for posts with sound.
Doing this requires doing `.includes(:media_asset)` in a bunch of
places to avoid N+1 queries when we access the post's duration.
Refactor CSS to use standard Tailwind-style utility classes instead of
ad-hoc rules. This eliminates a lot of single-purpose rules for specific
UI elements and standardizes margins to be more consistent throughout
the site.
Utility classes are defined manually on an as-needed basis instead of
importing Tailwind as a whole. Naming conventions mostly follow
Tailwind's conventions, otherwise they follow Bootstrap.
* https://tailwindcss.com/docs/
* https://getbootstrap.com/docs/5.0/utilities/spacing/
Refactor the post preview html to use the ViewComponent framework. This
lets us encapsulate all the HTML, CSS, and helper methods for a UI
component in a single place.
See https://viewcomponent.org.
Standardize on using `show_deleted: true` instead of `tags: "status:any"`
when rendering thumbnails and we want to show deleted thumbnails.
Also fixes it so that deleted thumbnails are shown when reordering pools
and favorite groups.
