Polish various polish

[jasmussen]

This PR does a few things:

• It makes it so that the Publish button doesn't change label when it's just saving. This likely needs more work, as we actually do want this label to change when you are clicking update on an already published post.
• It adds bottom padding to the post, which makes for a better experience on longer posts — as you near the end, there's space to scroll down so the Inserter doesn't sit too snuggly near the bottom of the post.
• It fixes issues with the Placeholder block paddings and margins, so it now looks exactly like the text block it's supposed to emulate. It no longer jumps in paddings.
• It polishes the toolbar on the Classic Text block, so it's also no longer jumpy.
• It colorizes the little arrow on the left in the admin menu white, so it matches the body content.

Screenshots

[codecov]

Codecov Report

Merging #3717 into master will not change coverage.
The diff coverage is 100%.

@@           Coverage Diff           @@
##           master    #3717   +/-   ##
=======================================
  Coverage   37.45%   37.45%           
=======================================
  Files         277      277           
  Lines        6707     6707           
  Branches     1222     1222           
=======================================
  Hits         2512     2512           
  Misses       3536     3536           
  Partials      659      659

Impacted Files	Coverage Δ
editor/components/post-publish-button/label.js	87.5% <100%> (ø)	⬆️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 0ad2621...1685c50. Read the comment docs.

[mcsf]

Nice changes! Things look good to me, just wondering if some of the magic numbers in the CSS should become proper variables.

[jasmussen]

Nice changes! Things look good to me, just wondering if some of the magic numbers in the CSS should become proper variables.

I hear you, and I have a separate to-do item to look at converting more stuff to variables separately, because it's a more holistic task given the recent changes in block border widths and paddings. I think I can clean up a lot.

But the number for the double-stacked Classic Text toolbar is hard to convert to variables, as it's definitely an entirely custom toolbar type. I'll look at it, but I prefer to do that separately.

[mtias]

Going to merge this.

[gziolo]

Please note the inserter under Toolbar. We might want to improve experience around that.

[gziolo]

Abother one:

[youknowriad]

I think those styles should be moved out of the editor/components directory. Because they only make sense in the edit-post layout (not in p2 for example). In editor/components we should think of the components (and styles) as reusable components that should look good when inserting them but if we want to position them properly etc... it should be done in the "layout" IMO.

In general, I do this in the. modes/visual-editor/style.scss by specifying the parent .editor-visual-editor +.editor-default-block-appender {

[jasmussen]

Please note the inserter under Toolbar. We might want to improve experience around that.

I think that should be opened as a separate issue.

I'll try and fix the stylesheet changes you suggested Riad.