The user should be able to click on any item in the media gallery modal and navigate to a larger view of the media content.
The designs are viewable on [[ https://www.figma.com/file/a1nkbWgbgjRlrOY9LVurTz/Comm-%2F-Desktop-app?node-id=8345%3A137716&t=EvoYpj3N8EtOXW7J-0 | Figma ]].
Linear: https://linear.app/comm/issue/ENG-3016/allow-media-gallery-items-to-click-through-to-a-full-screen-view-on
I've created a separate [[ https://linear.app/comm/issue/ENG-3143/restyle-multimediamodal | task ]] to track the restyling of `MultimediaModal` as I'm currently discussing it with Ted.
Depends on D6864