Multi-selected blocks + contentOnly representations: always show text styles if range includes text

[jasmussen]

If you select two paragraphs, you get text formatting tools across, in the inspector:

If you select two image blocks, you get image formatting tools across, in the inspector:

If you select mixed content, such as a paragraph and an image, you get no controls at all, in the inspector:

This is not very useful.

Proposed solution

If you have a mixed selection that includes text, always show the text formatting tools.

[Mamaduka]

IIRC, this is intentional. The inspector controls are only displayed when blocks of the same type are selected since they share attribute definitions.

Side note: Multi-editing blocks have their issues when specific changes might get lost. See #51609 and #41260.

[jasmussen]

Yes, it definitely feels intentional so I'm not suggesting this as a bug, or even an urgent one, can be 6.8. But mainly, it feels like whenever you have text blocks as part of your selection, surfacing text-block attributes across is worth it. Kind of like how you might select across text and images in a Google Doc and change press ⌘B, you'd at least make the text bold even if not the image. So it's a writing flow suggestion with lowish priority.

[jasmussen]

Updated this issue to include that these tools should also be shown in contentOnly representations!