Hide sensitive banner images by default

[elegaanz]

Is your feature request related to a problem? Please describe.

One may set an image that is marked as sensitive as article banner, and thus it may be visible on the homepage (and on other pages listing articles, like user profile).

Also, I don't really know what to do with blog/user banner and avatars, but something similar should probably be done?

Describe the solution you'd like

These images should be hidden under a CW, as they are in the body of articles. On the article page itself it can probably be visible by default, as people have chosen to read this article knowing there was a CWed image?

Describe alternatives you've considered

Not showing them at all, but this is probably too much.

Or making it impossible to set a sensitive image as article banner.

~~Additional context~~