Making `size=full` images have a shadow and be inline-block so the space next to them isn't clickable Fixes #4902

Summary: Added .phabricator-remarkup-embed-image to full size images as well

Test Plan: Add an image e.g. `{F123, size=full}` and verify that it has a shadow and the space next to it isn't clickable

Reviewers: chad, epriestley, #blessed_reviewers

Reviewed By: epriestley, #blessed_reviewers

Subscribers: chad, epriestley, Korvin

Maniphest Tasks: T4902

Differential Revision: https://secure.phabricator.com/D8858