Tiled Galleries: improve layout when printing

When printing Tiled Galleries, the image layout gets broken because of the lack of Javascript. Things get worse when lazy loading the images, and shown in this thread:
https://wordpress.org/support/topic/tiled-gallery-printing-javascript

It'd be nice to come up with a better tiled layout just for print.

Review the Tiled Galleries printing behavior and the linked WordPress support thread first, focusing on how the layout behaves without JavaScript and when images are lazy-loaded. Done means printed galleries retain a usable tiled layout and do not break when JavaScript is unavailable or lazy loading is enabled; the issue names no files or tests to start from.

Written by the indexing model from the issue text.