This commit fixes a regression whereby requests to global styles endpoints were not being preloaded, resulting in several requests being fired clientside unnecessarily.
For performance reasons, we preload the requests so that the data is in the editor store and ready to use straight away.
The outcome is that the editor loads more quickly.
Follow-up to [62042].
Props ellatrix, ramonopoly, apermo, peterwilsoncc.
Fixes #62315.
Built from https://develop.svn.wordpress.org/trunk@59316
git-svn-id: http://core.svn.wordpress.org/trunk@58702 1a063a9b-81f0-0310-95a4-ce76da25c4cd