cover: tweak styles:

- `optimizeQuality` > `smooth` (CSS language evolution)
- Use `auto` instead of a fixed width.
- Add exceptions for heights and apply them to some previously modified templates.
- Remove `is-large` exception.
- Widen the content column on list curation.

bookwyrm/templates/book/editions.html

@@ -16,7 +16,7 @@
     <div class="columns">
         <div class="column is-2">
             <a href="/book/{{ book.id }}">
-                {% include 'snippets/book_cover.html' with book=book cover_class='is-medium' %}
+                {% include 'snippets/book_cover.html' with book=book cover_class='is-h-medium' %}
             </a>
         </div>
         <div class="column is-7">