Individual expand/collapse of image/website previews

While inline image/wesite previews are great, sometimes they can make the chat area a bit too cluttered.

Idea:
1. If `Expand URL to media` is checked, add a way to collapse each image/website preview individually.
2. If `Expand URL to media` is unchcked, add a way to expand each image/website preview individually

Start by searching for the `Expand URL to media` setting and the code that renders inline image and website previews in the chat area. Done means each preview can be collapsed when the setting is enabled and expanded when it is disabled, independently of the other previews.

Written by the indexing model from the issue text.