Blocks: Extract and factorize block alignment controls

[youknowriad]

This PR continues our Refactoring to move the controls to the edit function.

Testing instructions

• Block Alignment controls for the button, image, embed and table block should continue the work the way they work on master.

[aduth]

Is this different in purpose than #987 ? How does it relate?

[youknowriad]

Isn't #987 about text alignments? or do you think we can reuse it?

[aduth]

#987 is mainly toward a goal of letting alignment be a consideration of the block as a whole, not individual paragraphs. So seems similar in purpose to what you've proposed here, though your changes include a handful more blocks.

[youknowriad]

But don't you think we should keep distinction between TextAlignmentToolbar and BlockAlignmentToolbar ? Even if the internals are close, and could share some code, having two different components could be a good thing.

[aduth]

Hmm, what would be the practical difference between the two? Seems they only really vary in the icons they render. Both assume a callback is to be passed to specify the actual change implementation.

[youknowriad]

yes, the icons are the only differences but sometimes it's good to duplicate code for clarity. A component could have both. These are the two toolbars we have for now, but we may have other reusable toolbars a block author could use. I see them as a meaningful group of controls instead of a more generic toolbar component with maybe unrelated controls to pick.

Anyway, this is just an idea, the generic "toggle" toolbar is a possibility too.

[aduth]

Yeah, not so opposed to the idea of duplication as much as questioning whether a distinction between text alignment vs. block alignment is really one we care to make, or is in-fact more clear.

Maybe cc @jasmussen @mtias to this point.

[youknowriad]

I'm keen to move these two (PRs #987 and this one) forward to remove the controls property from the block API.

[aduth]

Dunno if we might want to hold off on this in our push toward a stable release this week since it's not really fixing or adding anything.

[aduth]

Consistency: __

[aduth]

I think we want icon: 'align-wide'

[youknowriad]

Ok to postpone :)

Rebased, should be ok to review. Let's get this merged before the plugin release