In [54358], styling for Button blocks that had been removed from classic themes was reintroduced. However, it was added with a global scope, whereas editor styles are usually added with a `.editor-styles-wrapper` selector, which makes them more specific.
This change modifies the way that classic theme styles are added so that they also get wrapped in an `.editor-styles-wrapper` selector to match specificity.
Furthermore, adjust specificity for some Button block related styling in the editor for the Twenty Twelve and Twenty Twenty themes.
Merges [https://github.com/WordPress/gutenberg/pull/44731 Gutenberg PR 44731] into trunk.
Follow-up to [54358].
Props scruffian, cbravobernal, sabernhardt, audrasjb.
See #56467.
Built from https://develop.svn.wordpress.org/trunk@54687
git-svn-id: http://core.svn.wordpress.org/trunk@54239 1a063a9b-81f0-0310-95a4-ce76da25c4cd
