Consider adding opacity controls to all image blocks

[annezazu]

What problem does this address?

This came up as a request in the FSE Outreach Program's All Things Media exploration:

An opacity slider for any type of image block.

What is your proposed solution?

Right now, there are different implementations for opacity between the color picker component (#37731) and a block like the Cover Block. In this case, this issue is opening a discussion around whether having a shared general implementation for block supports makes sense. If so, perhaps this could be a part of the background tools project: #16479

[hagege]

I would like to support and supplement this:
It would be nice if opacity could be set for blocks that are embedded with images and/or covers. Otherwise you can set this again only via custom css (which would not bother me personally, because I am anyway of the opinion, they should continue to offer additional CSS). Something like this: