[PRIVACY] Make the Image/Link Preview settings Client-Side

Please make the settings regarding image/link previews Client-side, instead of Account-side (or include both Account-side and Client-side settings). I don't want to have to keep changing the setting every time I'm about to switch from my personal devices to my work devices, and vice-versa.

Similarly, allowing you to configure alternate settings for specific servers and/or age-restricted channels can prevent some rather compromising situations when you click on a channel notification and see something you're not expecting to see right as somebody is about to look over your shoulder.