Add left/right alignment support to the group block

[cbirdsong]

What problem does this address?

A floating sidebar with text is a common pattern in design:

Right now, the only generic way¹ to do this in the editor is with the cover block. This works, but the cover block's default styling/settings expect it to have an image background and are not a great fit for text.

What is your proposed solution?

Add left/right alignment controls to the group block.

Footnotes

1. This is possible with the quote block, but then it would be a <blockquote>, and that might not be semantically correct. ↩

[burnuser]

Also suggested in: #47114

[jordesign]

Closing in favour of #47114

[annezazu]

Looks like this didn't actually get closed so closing out properly :D