Try attached container for the block movers.

[kjellr]

Alternate to #17216. As proposed in #16580 (comment).

Still a little buggy, but this is a rough first implementation of adding an attached block container around the block movers:

• Needs revised focus states
• Needs to be revised so that it works on short blocks (like one-line paragraphs)
• Needs to include a treatment for wide/full blocks

[shaunandrews]

I strongly prefer the pill shape you have in #17216 — this squared version feels too “blocky” (heh) and blends in with the block toolbar. Having the controls attached also leads to the block feeling very heavy when focused.

[kjellr]

Closing this one now that #17216 has been merged.