Add nested dropdown to group as row, stack, or grid directly

[richtabor]

I was thinking through alternatives for #49524 — which aims to reduce the steps it takes to group blocks as a row, stack or grid when I thought of leveraging nested dropdowns as an alternative.

As-is, you need to first group the blocks via the block options > "Group" control, then open the block inspector and select one of the variant icons from the card up top. This idea explores leveraging the pending nested dropdown support, allowing for direct transforming between each of the group variations.

I don't love "Group" > "Group". Perhaps "Group as..." could be an alternative, or some other copy to convey grouping/wrapping.

Related: #50459, #49271

Visual

[hanneslsm]

From the ideas from #49524 I like this the most.
"Group as…" also works very well and explains easily the mental model that rows, stacks and grids are actually Group block variations.

I only wonder if the nested dropdown adds friction again. It really depends on how fast and intuitively the nested level opens.
To get around it we could introduce a shortcut for grouping blocks (by the way, thinking out lout here… will/would the shortcut and an icon work in the menu?) Edit: I just saw the DropdownMenu v2 in Stylebook All my doubts are gone. Nice! @ciampo Very well done!

[mtias]

Could also call the menu "Layout" to not repeat "Group".

[richtabor]

Could also call the menu "Layout" to not repeat "Group".

I like that.