Query Loop Block: develop a content-only representation

[annezazu]

Similar to #65699, we need to think about the experience of interacting with the Query Loop block when in Write mode/content only. As it stands right now, the experience is quite confusing as the only items you can edit or change when viewing a homepage aren't items most will need to change. For example, here's a video showing how in Write mode, the only piece you can edit is the no results message:

no.results.found.query.loop.content.only.mov

When testing this with loved ones (I can ask for permission to share some of the video), repeatedly folks would edit this text as it was the only thing offered to them to edit in much of the homepage! Similar to the navigation block, we need to find a way to open up some controls and options while also clarifying the current limitations to know when to switch into Design mode.

[richtabor]

What about surfacing alternate designs, like here: #63497, so you can essentially swap out blog designs. We already have "Replace" in the toolbar.

[jasmussen]

I like that, and it pairs well with the fact that the loop placeholder block also allows you to pick from those options.

[richtabor]

Let's try that to start, before surfacing additional controls in write mode.

[ramonjd]

Let's try that to start, before surfacing additional controls in write mode.

I started a WIP PR for #63497 over at #66993