Image Tools: Add dedicated toolbar section

[jasmussen]

The crop and rotate tools for the Image block currently append themselves in the block toolbar when the edit button is clicked:

This can be a bit disorienting as the toolbar is changing modes, without visualizing this.

@javierarce and @critterverse did a number of good explorations on secondary toolbars. Based on these explorations, and work in progress in #37337, we could embrace a secondary toolbar state for image tools, like so:

See also:

• Image: Improve the inspector, adopt the unified dimensions panel #38068
• Make it easier to quickly turn duotone on/off #38556
• Duotone: Duotone filter button should always be at the end #31373
• Image Block: Surface aspect-ratio tool for custom image dimensions #38990
• Duotone/Filters: Presets only in block toolbar, advanced filtering in inspector #39452

[richtabor]

I think its definitely a better experience than what we have today.

What I'm a bit hesitant on though is the "Back" button, which looks/feels just like the parent block selector we have in place:

What's the objection to having a popover toolbar? Like the heading block used to have, or like the link control does in the image block? Is it that we'd be blocking out part of the visual of the image itself?

[jasmussen]

The back button was intentionally separated in order to use the same language as the "up" button. Do you think that's problematic? Worst case, it can work decently well with the button part of the same toolbar:

What's the objection to having a popover toolbar? Like the heading block used to have, or like the link control does in the image block? Is it that we'd be blocking out part of the visual of the image itself?

You're referring to the zoom control here, right? Yes indeed, part of it is covering the image. The following is more of an issue that emerged from some separate Duotone efforts, but covering the majority of the image was problematic there:

Incidentally that led to the presets-only duotone mockup here, which happens to also have global styles benefits. But the realization was the same, there are simple benefits to controls living in the block toolbar, especially when the image is very small, or sits in a constrained nested context.

That's not to say we absolutely can't have popovers. The aspect ratio remains a dropdown, and I would also imagine the zoom moving to the block toolbar not necessarily happening as the first effort, since there are some keyboard-interaction flows there that are important to figure out.

[richtabor]

The back button was intentionally separated in order to use the same language as the "up" button. Do you think that's problematic?

Maybe not problematic, but potentially a confusion point. I think it works better outside the main toolbar area.

After testing a few things a bit more I think this approach makes the best sense. Same for duotone.