[performance] Images on reading list should have width and height attributes.

### Relevant url?
https://openlibrary.org/people/jdlrobson/books/want-to-read

### Steps to Reproduce
On https://openlibrary.org/people/jdlrobson/books/want-to-read because the cover images have no width and height associated, there is an unnecessary re-render of the page.

Expected: Space for covers is allocated and does not shift once the images are loaded.

### Details

- **Logged in (Y/N)?**
- **Browser type/version?**
- **Operating system?**
- **Environment (prod/dev/local)?** prod

### Proposal & Constraints

### Related files

### Stakeholders
@jdlrobson