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.
Replace references to the `is_resolved` field with the `status` field.
Post flags were marked as resolved when a post was approved (but not
when the post was deleted because it went unapproved). The status field
supercedes the resolved field.
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.
Ensure dtext is always wrapped in a `<div class="prose">` or
`<span class="prose">` (for inline dtext) container so that dtext css is
properly applied.