FIX: Support pausing GIFs for giphy/tenor oneboxes (PR #13194)

Followup to FEATURE: Enable pausing images from Giphy and Tenor (#13185) · discourse/discourse@726500b · GitHub, this ensures oneboxes from Giphy/Tenor can also be paused.

Previously, we were also linking to the source image on click (opening in a new window), those links have been removed because they conflict with the pause action on click.